Systems and methods for energy storage using phosphorescence and waveguides

ABSTRACT

Provided herein are systems and methods for storing energy. A photon battery assembly may comprise a light source, phosphorescent material, a photovoltaic cell, and a waveguide. The phosphorescent material can absorb optical energy at a first wavelength from the light source and, after a time delay, emit optical energy at a second wavelength after a time delay. The photovoltaic cell may absorb the optical energy at the second wavelength and generate electrical power. In some instances, a first waveguide may be configured to direct the optical energy at the first wavelength from the light source to the phosphorescent material and/or a second waveguide may be configured to direct the optical energy at the second wavelength from the phosphorescent material to the photovoltaic cell.

CROSS-REFERENCE

This application is a continuation-in-part of U.S. patent applicationSer. No. 16/826,604, filed Mar. 23, 2020, which is a continuation ofU.S. patent application Ser. No. 16/516,801, filed Jul. 19, 2019, whichis a continuation of International Patent Application No.PCT/US19/020592, filed Mar. 4, 2019, which claims benefit of U.S.Provisional Application No. 62/638,646, filed Mar. 5, 2018, each ofwhich applications is entirely incorporated herein by reference for allpurposes.

BACKGROUND

Especially in an age where so many activities and functions depend on acontinuous supply of power, lapses or interruptions in the provision ofpower may lead to highly undesirable results. These recent years haveseen a fast-growing market for readily accessible power, such as inbatteries, supercapacitors, fuel cells, and other energy storagedevices. However, such energy storage devices are often limited in manyaspects. For example, they may be volatile or unstable under certainoperating conditions (e.g., temperature, pressure) and becomeineffective or pose a safety hazard. In some cases, an energy storagedevice may itself be consumed during one or more cycles of converting orstoring energy and thus have limited lifetime. In some cases, a rate ofcharging may be too slow to effectively support or satisfy a rate ofconsumption of power.

SUMMARY

Recognized herein is a need for reliable systems and methods for energystorage. The systems and methods for energy storage disclosed herein mayprovide superior charging rates to those of conventional chemicalbatteries, for example, on the order of 100 times faster or more. Thesystems and methods disclosed herein may provide superior lifetimes tothose of conventional chemical batteries, for example, on the order of10 times more recharge cycles or more. The systems and methods disclosedherein may be portable. The systems and methods disclosed herein may bestable and effective in relatively cold operating temperatureconditions.

The systems and methods disclosed herein may use phosphorescent materialto store energy over a finite duration of time. For example, thephosphorescent material may store and/or convert energy with substantialtime delay. The systems and methods disclosed herein may use lightsources to provide an initial source of energy in the form of opticalenergy. The light sources can be artificial light sources, such as lightemitting diodes (LEDs). The systems and methods disclosed herein may usephotovoltaic cells to generate electrical power from optical energy. Insome embodiments, the systems and methods disclosed herein may useradioactive material to excite (or otherwise stimulate) thephosphorescent material. A system for energy storage may comprise alight source, a phosphorescent material, a photovoltaic cell, and awaveguide to direct waves between the light source and thephosphorescent material and/or between the photovoltaic cell and thephosphorescent material.

In an aspect, provided is a system for storing energy, comprising: alight source configured to emit optical energy at a first wavelengthfrom a surface of the light source; a phosphorescent material configuredto (i) absorb the optical energy at the first wavelength, and (ii) at arate slower than a rate of absorption, emit optical energy at a secondwavelength, wherein the second wavelength is greater than the firstwavelength; a photovoltaic cell adjacent to the phosphorescent material,wherein the photovoltaic cell is configured to (i) absorb optical energyat the second wavelength, and (ii) generate electrical power fromoptical energy; and a waveguide adjacent to the phosphorescent material,wherein the waveguide is configured to (i) direct the optical energy atthe first wavelength from the light source to the phosphorescentmaterial or (ii) direct the optical energy at the second wavelength fromthe phosphorescent material to the photovoltaic cell.

In some embodiments, the waveguide is configured to direct the opticalenergy at the first wavelength from the light source to thephosphorescent material and wherein the system comprises a secondwaveguide configured to direct the optical energy at the secondwavelength from the phosphorescent material to the photovoltaic cell. Insome embodiments, the second waveguide and the phosphorescent materialare concentric.

In some embodiments, the waveguide is configured to direct the opticalenergy at the first wavelength from the light source to thephosphorescent material, and wherein the waveguide is adjacent to thelight source. In some embodiments, the waveguide is in contact with thelight source.

In some embodiments, the waveguide is configured to direct the opticalenergy at the second wavelength from the phosphorescent material to thephotovoltaic cell, and wherein the waveguide is adjacent to thephotovoltaic cell. In some embodiments, the waveguide is in contact withthe photovoltaic cell.

In some embodiments, the waveguide comprises one or more reflectivesurfaces, wherein the reflective surfaces are configured to (i) directthe optical energy at the first wavelength from the light source to thephosphorescent material or (ii) direct the optical energy at the secondwavelength from the phosphorescent material to the photovoltaic cell. Insome embodiments, the waveguide comprises a plurality of reflectivesurfaces having increasingly large reflective surfaces along an opticalpath within the waveguide, such that a first set of waves from the lightsource are configured to be reflected at a first reflective surface ofthe plurality of reflective surfaces for excitation of a first volume ofphosphorescent material, and a second set of waves from the light sourceare configured to be reflected at a second reflective surface of theplurality of reflective surfaces for excitation of a second volume ofphosphorescent material, wherein the second volume of phosphorescentmaterial is disposed at a greater distance from the light source thanthe first volume of phosphorescent material.

In some embodiments, the light source is a light-emitting diode (LED).

In some embodiments, a rechargeable battery is electrically coupled tothe light source and the photovoltaic cell, and wherein at least part ofthe electrical power generated by the photovoltaic cell charges therechargeable battery, and wherein at least part of electrical powerdischarged by the rechargeable battery powers the light source.

In some embodiments, the phosphorescent material comprises strontiumaluminate and europium. In some embodiments, the phosphorescent materialcomprises dysprosium.

In some embodiments, the phosphorescent material comprises grains havinga particle size of less than about 5 micrometers.

In some embodiments, the phosphorescent material comprises grains havinga particle size of less than about 20 nanometers.

In some embodiments, the light source is adjacent to and in contact withthe waveguide.

In some embodiments, the light source is not in contact with thewaveguide and the phosphorescent material. In some embodiments, thelight source is located remote from the waveguide and the phosphorescentmaterial, wherein the light source is in optical communication with thewaveguide.

In some embodiments, the system further comprises a coating on thewaveguide, wherein the coating is in optical communication with thewaveguide and the phosphorescent material, wherein the coating comprisesan optical filter. In some embodiments, the optical filter is a dichroicelement. In some embodiments, the optical filter is configured totransmit waves having the first wavelength from the waveguide to thephosphorescent material and reflect waves having the second wavelengthfrom the phosphorescent material back to the phosphorescent material. Insome embodiments, the coating is in contact with the waveguide and thephosphorescent material.

In another aspect, provided is a method for storing energy, comprising:(a) emitting optical energy at a first wavelength from a surface of alight source; (b) directing the optical energy at the first wavelength,via a first waveguide, to a phosphorescent material; (c) at a rateslower than a rate of absorption of the optical energy at the firstwavelength, emitting, by the phosphorescent material, optical energy ata second wavelength, wherein the second wavelength is greater than thefirst wavelength; (d) directing the optical energy at the secondwavelength, via a second waveguide, to a photovoltaic cell, wherein thesurface of the photovoltaic cell is adjacent to the phosphor; and (e)generating electrical power from the optical energy at the secondwavelength.

In some embodiments, the second waveguide and the phosphorescentmaterial are concentric.

In some embodiments, the first waveguide is adjacent to the lightsource.

In some embodiments, the second waveguide is adjacent to thephotovoltaic cell.

In some embodiments, the first waveguide comprises one or morereflective surfaces, wherein the reflective surfaces are configured todirect the optical energy at the first wavelength from the light sourceto the phosphorescent material. In some embodiments, the first waveguidecomprises a plurality of reflective surfaces having increasingly largereflective surfaces along an optical path within the first waveguide,such that a first set of waves from the light source are configured tobe reflected at a first reflective surface of the plurality ofreflective surfaces for excitation of a first volume of phosphorescentmaterial, and a second set of waves from the light source are configuredto be reflected at a second reflective surface of the plurality ofreflective surfaces for excitation of a second volume of phosphorescentmaterial, wherein the second volume of phosphorescent material isdisposed at a greater distance from the light source than the firstvolume.

In some embodiments, the light source is a light-emitting diode (LED).

In some embodiments, a rechargeable battery is electrically coupled tothe light source and the photovoltaic cell, and wherein at least part ofthe electrical power generated by the photovoltaic cell charges therechargeable battery, and wherein at least part of electrical powerdischarged by the rechargeable battery powers the light source.

In some embodiments, the phosphorescent material comprises strontiumaluminate and europium. In some embodiments, the phosphorescent materialcomprises dysprosium.

In some embodiments, the phosphorescent material comprises grains havinga particle size of less than about 5 micrometers.

In some embodiments, the phosphorescent material comprises grains havinga particle size of less than about 20 nanometers.

In some embodiments, the light source is in contact with the firstwaveguide.

In some embodiments, the light source is not in contact with the firstwaveguide and the phosphorescent material. In some embodiments, thelight source is located remote from the first waveguide and thephosphorescent material, wherein the light source is in opticalcommunication with the first waveguide.

In some embodiments, the first waveguide comprises a coating on thefirst waveguide, wherein the coating is in optical communication withthe first waveguide and the phosphorescent material, wherein the coatingcomprises an optical filter. In some embodiments, the optical filter isa dichroic element. In some embodiments, the optical filter isconfigured to transmit waves having the first wavelength from the firstwaveguide to the phosphorescent material and reflect waves having thesecond wavelength from the phosphorescent material back to thephosphorescent material. In some embodiments, the coating is in contactwith the waveguide and the phosphorescent material.

In another aspect, provided is a method for wireless charging,comprising: (a) providing a battery assembly comprising: aphosphorescent material configured to (i) absorb optical energy at afirst wavelength, and (ii) at a rate slower than a rate of absorption,emit optical energy at a second wavelength, wherein the secondwavelength is greater than the first wavelength; a photovoltaic celladjacent to the phosphorescent material, wherein the photovoltaic cellis configured to (i) absorb optical energy at the second wavelength, and(ii) generate electrical power from optical energy; and a waveguideadjacent to the phosphorescent material, wherein the waveguide isconfigured to (i) direct the optical energy at the first wavelength froma light source to the phosphorescent material or (ii) direct the opticalenergy at the second wavelength from the phosphorescent material to thephotovoltaic cell; and (b) providing optical energy at the firstwavelength from the light source to the waveguide, wherein the lightsource is not in contact with the waveguide and the phosphorescentmaterial, and wherein the light source is in optical communication withthe waveguide. emitting optical energy at a first wavelength from asurface of a light source, thereby charging the battery assembly.

In another aspect, provided is a system for storing energy, comprising:a light source configured to emit optical energy at a first wavelengthfrom a surface of the light source; a phosphorescent material adjacentto the surface of the light source, wherein the phosphorescent materialis configured to (i) absorb the optical energy at the first wavelength,and (ii) at a rate slower than a rate of absorption, emit optical energyat a second wavelength, wherein the second wavelength is greater thanthe first wavelength; and a photovoltaic cell adjacent to thephosphorescent material, wherein the photovoltaic cell is configured to(i) absorb optical energy at the second wavelength through a surface ofthe photovoltaic cell, and (ii) generate electrical power from opticalenergy.

In some embodiments, the light source is a light-emitting diode (LED).

In some embodiments, the photovoltaic cell is electrically coupled to anelectrical load. In some embodiments, at least part of the electricalpower generated by the photovoltaic cell powers the electrical load.

In some embodiments, the photovoltaic cell is electrically coupled tothe light source. In some embodiments, at least part of the electricalpower generated by the photovoltaic cell powers the light source.

In some embodiments, a rechargeable battery is electrically coupled tothe light source and the photovoltaic cell. In some embodiments, atleast part of the electrical power generated by the photovoltaic cellcharges the rechargeable battery, and wherein at least part ofelectrical power discharged by the rechargeable battery powers the lightsource.

In some embodiments, the first wavelength is an ultraviolet wavelength.

In some embodiments, the second wavelength is a visible wavelength.

In some embodiments, the phosphorescent material comprises strontiumaluminate and europium.

In some embodiments, the system further comprises a radioactive materialthat emits high energy particles, wherein the high energy particles arecapable of travelling through the phosphorescent material, wherein thephosphorescent material is configured to (i) absorb kinetic energy fromthe high energy particles, and (ii) at a rate slower than the rate ofabsorption of kinetic energy, emit optical energy at the secondwavelength.

In some embodiments, the phosphorescent material is adjacent to theradioactive material. In some embodiments, the phosphorescent materialcomprises the radioactive material. In some embodiments, the radioactivematerial is strontium-90.

In some embodiments, the photovoltaic cell comprises a plurality ofdepressions between protrusions and wherein the surface of thephotovoltaic cell is a surface of a protrusion defining a depression.

In another aspect, provided is a method for storing energy, comprising:emitting optical energy at a first wavelength from a surface of a lightsource; absorbing, by a phosphorescent material adjacent to the surfaceof the light source, the optical energy at the first wavelength; at arate slower than a rate of absorption, emitting, by the phosphorescentmaterial, optical energy at a second wavelength, wherein the secondwavelength is greater than the first wavelength; absorbing the opticalenergy at the second wavelength through a surface of a photovoltaiccell, wherein the surface of the photovoltaic cell is adjacent to thephosphor; and generating electrical power from the optical energy at thesecond wavelength.

In some embodiments, the light source is a light-emitting diode (LED).

In some embodiments, the method can further comprise powering anelectrical load electrically coupled to the photovoltaic cell using theelectrical power. For example, the electrical load can be a mobiledevice. In another example, the electrical load can be an electric car.

In some embodiments, the method can further comprise powering the lightsource using at least part of the electrical power, wherein the lightsource is electrically coupled to the photovoltaic cell.

In some embodiments, the method can further comprise charging arechargeable battery using at least part of the electrical power,wherein the rechargeable battery is electrically coupled to thephotovoltaic cell. In some embodiments, the method can further comprisepowering the light source using at least part of electrical powerdischarged by the rechargeable battery, wherein the rechargeable batteryis electrically coupled to the light source.

In some embodiments, the first wavelength is an ultraviolet wavelength.

In some embodiments, the second wavelength is a visible wavelength.

In some embodiments, the phosphorescent material comprises strontiumaluminate and europium.

In some embodiments, the photovoltaic cell comprises a plurality ofdepressions between protrusions and wherein the surface of thephotovoltaic cell is a surface of a protrusion defining a depression.

In another aspect, provided is a method for storing energy, comprising:emitting high energy particles from a radioactive material, wherein thehigh energy particles travel through a phosphorescent material;absorbing, by the phosphorescent material, kinetic energy from the highenergy particles; at a rate slower than a rate of absorption of thekinetic energy, emitting, by the phosphorescent material, opticalenergy; absorbing the optical energy through a surface of a photovoltaiccell, wherein the surface of the photovoltaic cell is adjacent to thephosphor; and generating electrical power from the optical energy.

In some embodiments, the radioactive material is adjacent to thephosphorescent material.

In some embodiments, the phosphorescent material comprises theradioactive material.

In some embodiments, the method can further comprise powering anelectrical load electrically coupled to the photovoltaic cell using theelectrical power.

In some embodiments, the optical energy is at a visible wavelength.

In some embodiments, the photovoltaic cell comprises a plurality ofdepressions between protrusions and wherein the surface of thephotovoltaic cell is a surface of a protrusion defining a depression.

Another aspect of the present disclosure provides a non-transitorycomputer readable medium comprising machine executable code that, uponexecution by one or more computer processors, implements any of themethods above or elsewhere herein.

Another aspect of the present disclosure provides a system comprisingone or more computer processors and computer memory coupled thereto. Thecomputer memory comprises machine executable code that, upon executionby the one or more computer processors, implements any of the methodsabove or elsewhere herein.

Additional aspects and advantages of the present disclosure will becomereadily apparent to those skilled in this art from the followingdetailed description, wherein only illustrative embodiments of thepresent disclosure are shown and described. As will be realized, thepresent disclosure is capable of other and different embodiments, andits several details are capable of modifications in various obviousrespects, all without departing from the disclosure. Accordingly, thedrawings and description are to be regarded as illustrative in nature,and not as restrictive.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication, patent, or patent application wasspecifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings (also “Figure” and “FIG.” herein) of which:

FIG. 1 shows an exemplary photon battery assembly.

FIG. 2 shows a photon battery in communication with an electrical load.

FIG. 3 shows an exemplary photon battery assembly in application.

FIG. 4A illustrates a photon battery assembly with a waveguide.

FIG. 4B illustrates a photon battery assembly with a coating comprisingan optical filter.

FIG. 5 illustrates another photon battery assembly with a waveguide.

FIG. 6 illustrates another photon battery assembly with waveguides.

FIG. 7 shows a stack of a plurality of photon battery assemblies.

FIG. 8 shows an exploded view of another configuration for a photonbattery assembly stack with hollow core waveguides.

FIG. 9 illustrates a partial cross-sectional side view of the photonbattery assembly stack of FIG. 8.

FIG. 10 illustrates a method of storing energy in a photon battery.

FIG. 11 shows a computer system configured to implement systems andmethods of the present disclosure.

FIG. 12 shows an exemplary photon battery assembly that isself-sustaining in part.

FIG. 13 shows an exemplary photon battery assembly in communication witha rechargeable battery.

FIG. 14 shows a stack of a plurality of photon battery assemblies.

FIG. 15 shows a cross-sectional side view of an exemplary trenchconfiguration of a photon battery assembly.

FIG. 16 shows a cross-sectional top view of an exemplary trenchconfiguration of a photon battery assembly.

FIG. 17 shows a photon battery assembly comprising radioactive material.

FIG. 18 shows a photon battery assembly comprising radioactive materialin the phosphorescent material.

FIG. 19 illustrates a method of storing energy in a photon battery.

FIG. 20 illustrates a method of storing energy in a photon battery usingradioactive material.

DETAILED DESCRIPTION

While various embodiments of the invention have been shown and describedherein, it will be obvious to those skilled in the art that suchembodiments are provided by way of example only. Numerous variations,changes, and substitutions may occur to those skilled in the art withoutdeparting from the invention. It should be understood that variousalternatives to the embodiments of the invention described herein may beemployed.

Provided herein are systems and methods for energy storage. The systemsand methods disclosed herein may use phosphorescent material to storeenergy over a significant duration of time, such as by making use of thetime-delayed re-emission properties of phosphorescent material. Forexample, the phosphorescent material may store and/or convert energywith substantial time delay. A light source can provide an initialsource of energy to the phosphorescent material in the form of opticalenergy. For example, the phosphorescent material may absorb opticalenergy from the light source at a first wavelength, and after a timedelay, emit optical energy at a second wavelength. The light source canbe an artificial light source, such as a light emitting diode (LED). Aphotovoltaic cell can generate electrical power from optical energy,such as from optical energy at the second wavelength that is emitted bythe phosphorescent material.

Alternatively or in addition, the phosphorescent material may absorbkinetic energy, and after a time delay, emit optical energy convertedfrom the kinetic energy to be absorbed by the photovoltaic cell. Forexample, radioactive material can excite the phosphorescent materialwith high energy particles (having high kinetic energy). In some cases,the phosphorescent material may itself comprise radioactive material.

A waveguide may direct waves, such as the optical energy from the lightsource at the first wavelength between the light source and thephosphorescent material and/or the optical energy at the secondwavelength between the phosphorescent material and the photovoltaiccell. Such waveguides may increase energy density and compactness of theenergy storage system. Beneficially, such waveguide may greatly increaseefficiency of the time-delayed optical energy transfer between thephosphorescent material and the light source and the photovoltaic cell,as well as facilitate efficient use of the available phosphorescentmaterial.

The systems and methods for energy storage disclosed herein may providesuperior charging rates to those of conventional chemical batteries, forexample, on the order of 100 times faster or more. The systems andmethods disclosed herein may provide superior lifetimes to those ofconventional chemical batteries, for example, on the order of 10 timesmore recharge cycles or more. The systems and methods disclosed hereinmay be portable. The systems and methods disclosed herein may be stableand effective in relatively cold operating temperature conditions.

Reference will now be made to the figures. It will be appreciated thatthe figures and features therein are not necessarily drawn to scale.

FIG. 1 shows an exemplary photon battery assembly. A photon batteryassembly 100 can comprise a light source 101, a phosphorescent material102, and a photovoltaic cell 103. The phosphorescent material may beadjacent to both the light source and the photovoltaic cell. Forexample, the phosphorescent material can be sandwiched by the lightsource and the photovoltaic cell. The phosphorescent material can bebetween the light source and the photovoltaic cell. While FIG. 1 showsthe light source, phosphorescent material, and photovoltaic cell as avertical stack, the configuration is not limited as such. For example,the light source, phosphorescent material, and photovoltaic cell can behorizontally stacked or concentrically stacked. The light source and thephotovoltaic cell may or may not be adjacent to each other. In someinstances, the phosphorescent material can be adjacent to alight-emitting surface of the light source. In some instances, thephosphorescent material can be adjacent to a light-absorbing surface ofthe photovoltaic cell.

Regardless of contact between the phosphorescent material 102 and lightsource 101, the phosphorescent material and the light source may be inoptical communication. For example, as described elsewhere herein, thephosphorescent material and the light source may be in opticalcommunication via a waveguide. Regardless of contact between thephosphorescent material and photovoltaic cell 103, the phosphorescentmaterial and the photovoltaic cell may be in optical communication. Forexample, as described elsewhere herein, the phosphorescent material andthe photovoltaic cell may be in optical communication via a waveguide.In some instances, the same waveguide may be configured to facilitateoptical communication between the phosphorescent material and thephotovoltaic cell and between the phosphorescent material and the lightsource.

The phosphorescent material 102 may or may not be contacting the lightsource 101. If the phosphorescent material and the light source are incontact, the phosphorescent material can interface a light-emittingsurface of the light source. The phosphorescent material and the lightsource can be coupled or fastened together at the interface, such as viaa fastening mechanism. In some instances, a support carrying the lightsource and/or a support carrying the phosphorescent material may becoupled or fastened together at the interface. Examples of fasteningmechanisms may include, but are not limited to, form-fitting pairs,hooks and loops, latches, staples, clips, clamps, prongs, rings, brads,rubber bands, rivets, grommets, pins, ties, snaps, velcro, adhesives,tapes, a combination thereof, or any other types of fasteningmechanisms. In some instances, the phosphorescent material may haveadhesive and/or cohesive properties and adhere to the light sourcewithout an independent fastening mechanism. For example, thephosphorescent material may be painted or coated on the light-emittingsurface of the light source. In some instances, the phosphorescentmaterial may be coated onto primary, secondary, and/or tertiary opticsof the light source. In some instances, the phosphorescent material maybe coated onto other optical elements of the light source. Thephosphorescent material and the light source can be permanently ordetachably fastened together. For example, the phosphorescent materialand the light source can be disassembled from and reassembled into thephoton battery assembly 100 without damage (or with minimal damage) tothe phosphorescent material and/or the light source. Alternatively,while in contact, the phosphorescent material and the light source maynot be fastened together.

If the phosphorescent material 102 and the light source 101 are not incontact, the phosphorescent material can otherwise be in opticalcommunication with a light-emitting surface of the light source, such asvia a waveguide. For example, the phosphorescent material can bepositioned in an optical path of light emitted by the light-emittingsurface of the light source. In some instances, there can be an air gapbetween the phosphorescent material and the light source. In someinstances, there can be another intermediary layer between thephosphorescent material and the light source. The intermediary layer canbe air or other fluid. The intermediary layer can be a light guide oranother layer of optical elements (e.g., lens, reflector, diffusor, beamsplitter, etc.). In some instances, there can be a plurality ofintermediary layers between the phosphorescent material and the lightsource.

The phosphorescent material 102 may or may not be contacting thephotovoltaic cell 103. If the phosphorescent material and thephotovoltaic cell are in contact, the phosphorescent material caninterface a light-absorbing surface of the photovoltaic cell. Thephosphorescent material and the photovoltaic cell can be coupled orfastened together at the interface, such as via a fastening mechanism.In some instances, a support carrying the photovoltaic cell and/or asupport carrying the phosphorescent material may be coupled or fastenedtogether at the interface. In some instances, the phosphorescentmaterial may have adhesive properties and adhere to the photovoltaiccell without an independent fastening mechanism. For example, thephosphorescent material may be painted or coated on the light-absorbingsurface of the photovoltaic cell. In some instances, the phosphorescentmaterial may be coated onto primary, secondary, and/or tertiary opticsof the photovoltaic cell. In some instances, the phosphorescent materialmay be coated onto other optical elements of the photovoltaic cell. Thephosphorescent material and the photovoltaic cell can be permanently ordetachably fastened together. For example, the phosphorescent materialand the photovoltaic cell can be disassembled from and reassembled intothe photon battery assembly 100 without damage (or with minimal damage)to the phosphorescent material and/or the photovoltaic cell.Alternatively, while in contact, the phosphorescent material and thephotovoltaic cell may not be fastened together.

If the phosphorescent material 102 and the photovoltaic cell 103 are notin contact, the phosphorescent material can otherwise be in opticalcommunication with a light-absorbing surface of the photovoltaic cell.For example, the light-absorbing surface of the photovoltaic cell can bepositioned in an optical path of light emitted by the phosphorescentmaterial. In some instances, there can be an air gap between thephosphorescent material and the photovoltaic cell. In some instances,there can be another intermediary layer between the phosphorescentmaterial and the photovoltaic cell. The intermediary layer can be air orother fluid. The intermediary layer can be a light guide, lightconcentrator, or another layer of optical elements (e.g., lens,reflector, diffusor, beam splitter, etc.). In some instances, there canbe a plurality of intermediary layers between the phosphorescentmaterial and the photovoltaic cell.

In some instances, the photon battery assembly 100 can be assembled ordisassembled, such as into the light source 101, phosphorescent material102, or the photovoltaic cell 103 independently, or intosub-combinations thereof. In some instances, the photon battery assemblycan be assembled or disassembled without damage to the different partsor with minimal damage to the different parts.

In some instances, the photon battery assembly 100 can be housed in ashell, outer casing, or other housing. The photon battery assembly 100,and/or shell thereof can be portable. For example, the photon batteryassembly can have a maximum dimension of at most about 1 meter (m), 90centimeters (cm), 80 cm, 70 cm, 60 cm, 50 cm, 45 cm, 40 cm, 35 cm, 30cm, 25 cm, 20 cm, 15 cm, 10 cm, 9 cm, 8 cm, 7 cm, 6 cm, 5 cm, orsmaller. A maximum dimension of the photon battery assembly may be adimension of the photon battery assembly (e.g., length, width, height,depth, diameter, etc.) that is greater than the other dimensions of thephoton battery assembly. Alternatively, the photon battery assembly mayhave greater maximum dimensions. For example, a photon battery assemblyhaving a higher energy storage capacity can have larger dimensions andmay not be portable.

The light source 101 can be an artificial light source, such as a lightemitting diode (LED) or other light emitting device. For example, thelight source can be a laser or a lamp. The light source can be aplurality of light emitting devices (e.g., a plurality of LEDs). In someinstances, the light source can be arranged as one LED. In someinstances, the light source can be arranged as rows or columns ofmultiple LEDs. The light source can be arranged as arrays or grids ofmultiple columns, rows, or other axes of LEDs. The light source can be acombination of different light emitting devices. A light emittingsurface of the light source can be planar or non-planar. A lightemitting surface of the light source can be substantially flat,substantially curved, or form another shape.

The light source can be supported by rigid and/or flexible supports. Forexample, the supports can direct the light emitted by the light sourceto be directional or non-directional. In some instances, the lightsource can comprise primary and/or secondary optical elements. In someinstances, the light source can comprise tertiary optical elements. Insome instances, the light source can comprise other optical elements atother levels or layers (e.g., lens, reflector, diffusor, beam splitter,etc.). The light source can be configured to convert electrical energyto optical energy. For example, the light source can be powered by anelectrical power source, which may be external or internal to the photonbattery assembly 100. The light source can be configured to emit opticalenergy (e.g., as photons), such as in the form of electromagnetic waves.In some instances, the light source can be configured to emit opticalenergy at a wavelength or a range of wavelengths that is capable ofbeing absorbed by the phosphorescent material 102. For example, thelight source can emit light at wavelengths in the ultraviolet range(e.g., 10 nanometers (nm) to 400 nm). In some instances, the lightsource can emit light at other wavelengths or ranges of wavelengths inthe electromagnetic spectrum (e.g., infrared, visible, ultraviolet,x-rays, etc.).

In some instances, the light source 101 can be a natural light source(e.g., sun light), in which case the phosphorescent material 102 in thephoton battery assembly 100 may be exposed to the natural light sourceto absorb such natural light.

The phosphorescent material 102 can absorb optical energy at a firstwavelength (or first wavelength range) and emit optical energy at asecond wavelength (or second wavelength range) after a substantial timedelay. The second wavelength can be a different wavelength than thefirst wavelength. The optical energy at the first wavelength that isabsorbed by the phosphorescent material can be at a higher energy levelthan the optical energy at the second wavelength that is emitted by thephosphorescent material. The second wavelength can be greater than thefirst wavelength. In an example, the phosphorescent material can absorbenergy at ultraviolet range wavelengths (e.g., 10 nm to 400 nm) and emitenergy at visible range wavelengths (e.g., 400 nm to 700 nm). Forexample, the phosphorescent material can absorb blue photons and, aftera time delay, emit green photons. The phosphorescent material can absorboptical energy (e.g., photons) at other wavelengths (or ranges ofwavelengths) and emit optical energy at other wavelengths (or ranges ofwavelengths), such as in the electromagnetic spectrum (e.g., infrared,visible, ultraviolet, x-rays, etc.) wherein the energy emitted is at alower energy level than the energy absorbed. A rate of emission ofoptical energy by the phosphorescent material can be slower than a rateof absorption of optical energy by the phosphorescent material. Anadvantage of this difference in rate is the ability of thephosphorescent material to release energy at a slower rate thanabsorbing such energy, thus storing the energy during such time delay.

The phosphorescent material 102 can be crystalline, solid, liquid,ceramic, in powder form, granular or other particle form, liquid form,or in any other shape, state, or form. The phosphorescent material canbe long-lasting phosphors. In an example, the phosphorescent materialcan comprise strontium aluminate doped with europium (e.g., SrAl₂O₄:Eu).Some other examples of phosphorescent material can include, but are notlimited to, zinc gallogermanates (e.g., Zn₃Ga₂Ge₂O₁₀:0.5% Cr³⁺), zincsulfide doped with copper and/or cobalt (e.g., ZnS:Cu, Co), strontiumaluminate doped with other dopants, such as europium, dysprosium, and/orboron (e.g., SrAl₂O₄:Eu²⁺, Dy³⁺, B³⁺), calcium aluminate doped witheuropium, dysprosium, and/or neodymium (e.g., CaAl₂O₄:Eu²⁺, Dy³⁺, Nd³⁺),yttrium oxide sulfide doped with europium, magnesium, and/or titanium,(e.g., Y₂O₂S:Eu³⁺, Mg²⁺, Ti⁴⁺), and zinc gallogermanates (e.g.,Zn₃Ga₂Ge₂O₁₀:0.5% Cr³⁺). In some instances, the phosphorescent materialmay be provided in granular or other particle form. Such grain orparticle may have a maximum diameter of between about 1 and about 5micrometer. In some instances, the grain or particle may have a maximumdiameter of at least about 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8,1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2,3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6,4.7, 4.8, 4.9, 5.0 micrometers or more. Alternatively or in addition,the grain or particle may have a maximum diameter of at most about 5.0,4.9, 4.8, 4.7, 4.6, 4.5, 4.4, 4.3, 4.2, 4.1, 4.0, 3.9, 3.8, 3.7, 3.6,3.5, 3.4, 3.3, 3.2, 3.1, 3.0, 2.9, 2.8, 2.7, 2.6, 2.5, 2.4, 2.3, 2.2,2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0 micrometersor less.

In some instances, the afterglow (e.g., emitted optical energy) emittedby the phosphorescent material can last at least about 1 hour (hr), 2hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr, 9 hr, 10 hr, 11 hr, 12 hr, 1day, 2 days, 3 days, 4 days, 1 week, 2 weeks, 3 weeks, or longer. Insome instances, the phosphorescent material can store and/or dischargeenergy for at least about 1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8hr, 9 hr, 10 hr, 11 hr, 12 hr, 1 day, 2 days, 3 days, 4 days, 1 week, 2weeks, 3 weeks, or longer. Alternatively, the afterglow emitted by thephosphorescent material (or energy stored by the phosphorescentmaterial) can last for shorter durations.

In some instances, the phosphorescent material 102 may absorb opticalenergy at the first wavelength from any direction. In some instances,the phosphorescent material may emit optical energy at the secondwavelength in any direction (e.g., from a surface of the phosphorescentmaterial).

The assembly 100 can comprise one or a plurality of photovoltaic cells(e.g., photovoltaic cell 103) that are electrically connected in seriesand/or in parallel. The photovoltaic cell 103 can be a panel, cell,module, and/or other unit. For example, a panel can comprise one or morecells all oriented in a plane of the panel and electrically connected invarious configurations. For example, a module can comprise one or morecells electrically connected in various configurations. The photovoltaiccell 103, or solar cell, can be configured to absorb optical energy andgenerate electrical power from the absorbed optical energy. In someinstances, the photovoltaic cell can be configured to absorb opticalenergy at a wavelength or a range of wavelengths that is capable ofbeing emitted by the phosphorescent material 102. The photovoltaic cellcan have a single band gap that is tailored to the wavelength (or rangeof wavelengths) of the optical energy that is emitted by thephosphorescent material. Beneficially, this may increase the efficiencyof the energy storage system of the photon battery assembly 100. Forexample, for strontium aluminate doped with europium as thephosphorescent material, the photovoltaic cell can have a band gap thatis tailored to the green light wavelength (e.g., 500˜520 nm). Similarly,the light source 101 can be tailored to emit ultraviolet rangewavelengths (e.g., 20 nm to 400 nm). Alternatively, the photovoltaiccell can be configured to absorb optical energy at other wavelengths (orranges of wavelengths) in the electromagnetic spectrum (e.g., infrared,visible, ultraviolet, x-rays, etc.).

In some embodiments, organic light emitting diodes (OLEDs) can replacethe phosphorescent material 102 in the photon battery assembly 100. Insome embodiments, OLEDs can replace both the light source 101 and thephosphorescent material. OLEDs can be capable ofelectro-phosphorescence, where quasi particles in the lattice of thediodes store potential energy from an electric power source and releasesuch energy over time in the form of optical energy at visiblewavelengths (e.g., 400 nm to 700 nm). For example, OLEDs can be poweredby an electrical power source, which may be external or internal to thephoton battery assembly 100. A light-emitting surface of the OLEDs caninterface with a light-absorbing surface of the photovoltaic cell 103 tocomplete the photon battery assembly. For example, with OLEDs, thephotovoltaic cell can have a band gap that is tailored to the visiblewavelength range (e.g., 400˜700 nm).

The photovoltaic cell 103 may have any thickness. For example, thephotovoltaic cell may have a thickness of about 20 micrometers. In someinstances, the photovoltaic cell may have a thickness of at least about10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,28, 29, 30, 40, 50, 60, 70, 80, 90, 100 micrometers or more.Alternatively, the photovoltaic cell may have a thickness of at mostabout 100, 90, 80, 70, 60, 50, 40, 30, 29, 28, 27, 26, 25, 24, 23, 22,21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10 micrometers or less.

FIG. 2 shows a photon battery in communication with an electrical load.The photon battery 201 can power an electrical load 202. The photonbattery and the electrical load can be in electric communication, suchas via an electric circuit. While FIG. 2 shows a circuit, the circuitconfiguration is not limited to the one shown in FIG. 2. The electricalload can be an electrical power consuming device. The electrical loadcan be an electronic device, such as a personal computer (e.g., portablePC), slate or tablet PC (e.g., Apple® iPad, Samsung® Galaxy Tab),telephone, Smart phone (e.g., Apple® iPhone, Android-enabled device,Blackberry®), or personal digital assistant. The electronic device canbe mobile or non-mobile. The electrical load can be a vehicle, such asan automobile, electric car, train, boat, or airplane. The electricalload can be a power grid. In some cases, the electrical load can beanother battery or other energy storage system which is charged by thephoton battery. In some instances, the photon battery can be integratedin the electrical load. In some instances, the photon battery can bepermanently or detachably coupled to the electrical load. For example,the photon battery can be removable from the electrical load.

In some cases, a photon battery 201 can power a plurality of electricalloads in series or in parallel. In some cases, a photon battery canpower a plurality of electrical loads simultaneously. For example, thephoton battery can power 2, 3, 4, 5, 6, 7, 8, 9, 10 or more electricalloads simultaneously. In some cases, a plurality of photon batteries,electrically connected in series or in parallel, can power an electricalload. In some cases, a combination of one or more photon batteries andone or more other types of energy storage systems (e.g., lithium ionbattery, fuel cell, etc.) can power one or more electrical loads.

FIG. 3 shows an exemplary photon battery assembly in application. Anyand all circuits illustrated in FIG. 3 are not limited to such circuitryconfigurations. A photon battery assembly 300 can be charged by a powersource 304 and discharge power to an electrical load 306. The photonbattery assembly can comprise a light source 301, such as a LED or a setof LEDs. The light source can be in electrical communication with thepower source 304 through a port 305 of the light source. For example,the power source and the port 305 can be electrically connected via acircuit. The power source 304 may be external or internal to the photonbattery assembly 300. The power source can be a power supplying device,such as another energy storage system (e.g., another photon battery,lithium ion battery, supercapacitor, fuel cell, etc.). The power sourcecan be an electrical grid.

The light source 301 can receive electrical energy and emit opticalenergy at a first wavelength, such as via a light-emitting surface ofthe light source. The light-emitting surface can be adjacent to aphosphorescent material 302. The light source can be in opticalcommunication with the phosphorescent material. The phosphorescentmaterial can be configured to absorb optical energy at the firstwavelength and, after a time delay, emit optical energy at a secondwavelength. In some cases, the rate of emission of the optical energy atthe second wavelength can be slower than the rate of absorption of theoptical energy at the first wavelength. An advantage of this differencein rate is the ability of the phosphorescent material to release energyat a slower rate than absorbing such energy, thus storing the energyduring such time delay. In some instances, the phosphorescent materialcan store and/or discharge energy for at least about 1 hr, 2 hr, 3 hr, 4hr, 5 hr, 6 hr, 7 hr, 8 hr, 9 hr, 10 hr, 11 hr, 12 hr, 1 day, 2 days, 3days, 4 days, 1 week, 2 weeks, 3 weeks, or longer.

The photon battery assembly can comprise a photovoltaic cell 303. Thephotovoltaic cell can be configured to absorb optical energy at thesecond wavelength, such as via a light-absorbing surface of thephotovoltaic cell. The photovoltaic cell can be in optical communicationwith the phosphorescent material 302. The light-absorbing surface of thephotovoltaic cell can be adjacent to the phosphorescent material. Thephotovoltaic cell can generate electrical power from the optical energyabsorbed. The electrical power generated by the photovoltaic cell can beused to power an electrical load 306. The photovoltaic cell can be inelectrical communication with the electrical load through a port 307 ofthe photovoltaic cell. For example, the electrical load and the port 307can be electrically connected via a circuit.

The energy stored by the photon battery assembly 300 can be chargedand/or recharged multiple times. The power generated by the photonbattery assembly can be consumed multiple times. The photon batteryassembly can be charged and/or recharged by supplying electrical energy(or power) to the light source 301, such as through the port 305. Thephoton battery assembly 300 can discharge power by directing electricalpower generated by the photovoltaic cell to the electrical load 306,such as through the port 307. For example, the photon battery assembly300 can last (e.g., function for) at least 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 100, 500, 1000, 10⁴, 10⁵, 10⁶, or more recharge (or consumption)cycles.

The photon battery assembly 300 may provide superior charging rates tothose of conventional chemical batteries, for example, on the order of2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 timesfaster or more. For example, the photon battery assembly can charge at aspeed of at least about 800 watts per cubic centimeters (W/cc), 850W/cc, 900 W/cc, 1000 W/cc, 1050 W/cc, 1100 W/cc, 1150 W/cc, 1200 W/cc,1250 W/cc, 1300 W/cc, 1350 W/cc, 1400 W/cc, 1450 W/cc, 1500 W/cc orgreater. Alternatively, the photon battery assembly can charge at aspeed of less than about 800 W/cc. The photon battery assembly mayprovide superior lifetimes to those of conventional chemical batteries,for example, on the order of 2, 3, 4, 5, 6, 7, 8, 9, 10 times morerecharge cycles or more.

The photon battery assembly 300 may be stable and function effectivelyin relatively cold operating temperature conditions. For example, thephoton battery assembly may function stably in operating temperatures aslow as about −55° Celsius (° C.) and as high as about 65° C. The photonbattery assembly may function stably in operating temperatures lowerthan about −55° C. and higher than about 65° C. In some instances, thephoton battery assembly may function stably under any operatingtemperatures for which the light source (e.g., LEDs) functions stably.The photon battery assembly may not generate excess operating heat.

FIG. 12 shows an exemplary photon battery assembly that isself-sustaining in part. Any and all circuits illustrated in FIG. 12 arenot limited to such circuitry configurations. A photon battery assembly1200 can be charged by a power source 1204 (e.g., electrical grid,different energy storage system such as a battery, etc.) and dischargepower to an electrical load 1208. However, the electrical load 1208 orother electrical loads that may draw power from the photon batteryassembly may not necessarily be connected to the photon battery assemblyat all times. In some instances, the photon battery assembly maydischarge more power than is consumed by the electrical load connectedto the photon battery assembly. In such cases, at least some of thepower generated by the photovoltaic cell 1203 can be wasted or lost fromthe energy storage system (e.g., photon battery assembly 1200). When noelectrical load is connected to the photon battery assembly, in someinstances, the power generated by the photon battery assembly can bedirected back into the photon battery assembly. Alternatively or inaddition, when an electrical load is consuming a less amount of powerthan is being produced by the photon assembly, some of the power can bedirected into the photon battery assembly. For example, at least somepower generated by the photovoltaic cell can be directed to power thelight source 1201.

In some instances, the photon battery assembly 1200 in FIG. 12 andcorresponding components thereof can parallel the photon batteryassembly 300 in FIG. 3 and corresponding components thereof.

The photon battery assembly 1200 can comprise a light source 1201powered primarily by a power source 1204, such as through a first port1205 of the light source, a phosphorescent material 1202 adjacent to alight-emitting surface of the light source, and a photovoltaic cell1203, which light-absorbing surface of the photovoltaic cell is adjacentto the phosphorescent material. The photovoltaic cell can dischargepower to an electrical load 1208 when the electrical load is inelectrical communication with the photovoltaic cell. The photovoltaiccell can discharge power to the light source when the electrical load isnot in electrical communication with the photovoltaic cell.

For example, a circuitry of the photon battery assembly 1200 cancomprise a switch 1209 that either completes a first electric path 1210or a second electric path 1211. In some cases, the switch can completeneither electric path (e.g., as shown in FIG. 12), and when neitherelectric path is completed, the power generated by the photon batteryassembly can be wasted or lost from the energy storage system. The firstelectric path 1210 can be completed when no electrical load (e.g.,electrical load 1208) is connected to the photon battery assembly 1200.In some instances, completing the first electric path 1210 can be thedefault state of the switch 1209. When no electrical load is connected,the first electric path can be completed, thus directing the powergenerated by the photovoltaic cell 1203, such as through a port 1206 ofthe photovoltaic cell, to the light source 1201, such as through asecond port 1207 of the light source. In some cases, the first port 1205and the second port 1207 of the light source can be the same port.

The second electric path 1211 can be completed when at least oneelectrical load (e.g., electrical load 1208) is connected to the photonbattery assembly 1200. In some instances, connecting an electrical loadto the photon battery assembly can trigger the switch 1209 to alternatefrom a default path (or from completing a different electrical path) tocompleting the second electric path 1211. When an electrical load 1208is connected, the second electric path can be completed, thus directingthe power generated by the photovoltaic cell 1203, such as through theport 1206, to the electrical load 1208.

In some cases, the first electric path 1210 and the second electric path1211 can be mutually exclusive. In some cases, a circuit can connect theport 1206 of the photovoltaic cell 1203, the second port 1207 of thelight source 1201, and the electrical load 1208 in series or in paralleland simultaneously, or discretely, direct at least some power to thelight source and direct at least some power to the electrical load, suchas when more power is being discharged by the photovoltaic cell than isbeing consumed by the electrical load.

In some cases, the circuitry can be controlled manually (e.g., manualconnection of electrical load to photon battery assembly, such aspushing in a cable, nudges a switch component into a circuit position).Alternatively or in addition, the circuitry can be controlled by acontroller (not shown in FIG. 12). The controller may be capable ofsensing the connection(s) of one or more electrical loads with thephoton battery assembly. The controller may be capable of completingdifferent electrical circuit paths (e.g., first electric path 1210,second electric path 1211, etc.), such as via controlling one or moreswitch components (e.g., switch 1209) or other electrical components.

The controller can comprise one or more processors and non-transitorycomputer readable medium communicatively coupled to the one or moreprocessors. The controller, via the one or more processors and machinereadable instructions stored in memory, can be capable of regulatingdifferent charging and/or discharging mechanisms of the photon batteryassembly 1200. The controller may turn on an electrical connectionbetween the light source 1201 and the power supply 1204 to startcharging the photon battery assembly. The controller may turn off anelectrical connection between the light source and the power supply tostop charging the photon battery assembly. The controller may turn on oroff an electrical connection between the photovoltaic cell 1203 and theelectrical load 1208. In some instances, the controller may be capableof detecting a charge level (or percentage) of the photon batteryassembly. The controller may be capable of determining when the assemblyis completely charged (or nearly completely charged) or discharged (ornearly completely discharged). For example, the photon battery assemblymay further comprise a temperature sensor, heat sensor, optical sensor,or other type of sensor that is operatively coupled to the controller,wherein the sensors provide data indicative of charging level (orpercentage). In some instances, the controller may be capable ofmaintaining a certain range of charge level (e.g., 5%˜95%, 10%˜90%,etc.) of the photon battery assembly, such as to maintain and/orincrease the life of the photon battery assembly, which complete chargeor complete discharge can detrimentally shorten. The controller may becapable of determining a power consumption rate of an electrical loadand/or the light source. The controller may be configured to, based onsuch determination of power consumption rate, manipulate one or morecircuitry in the photon battery assembly to direct power to theelectrical load, the light source, both, and/or neither.

FIG. 13 shows an exemplary photon battery assembly in communication witha rechargeable battery. Any and all circuits illustrated in FIG. 13 arenot limited to such circuitry configurations. A photon battery assembly1300 can be charged by a power source 1304 and discharge power to anelectrical load 1309. However, the electrical load 1309 or otherelectrical loads that may draw power from the photon battery assemblymay not necessarily be connected to the photon battery assembly at alltimes. In such cases, the power generated by the photovoltaic cell 1303can be wasted or lost from the energy storage system (e.g., photonbattery assembly 1300). When no electrical load is connected to thephoton battery assembly, in some instances, the power generated by thephoton battery assembly can be directed to charge a rechargeable battery1308. For example, at least some power generated by the photovoltaiccell can be directed to charge the rechargeable battery 1308. Therechargeable battery 1308 can be electrically coupled to the photonbattery assembly 1300 such that the rechargeable battery can, in someinstances, supply power to a light source 1301, and in some instances,be charged by a photovoltaic cell 1303 of the photon battery assembly1300. The rechargeable battery can be a lithium ion battery.

In some instances, the photon battery assembly 1300 in FIG. 13 andcorresponding components thereof can parallel the photon batteryassembly 300 in FIG. 3 and corresponding components thereof. In someinstances, the photon battery assembly 1300 in FIG. 13 and correspondingcomponents thereof can parallel the photon battery assembly 1200 in FIG.12 and corresponding components thereof.

The photon battery assembly 1300 can comprise a light source 1301powered primarily by a power source 1304, such as through a first port1305 of the light source, a phosphorescent material 1302 adjacent to alight-emitting surface of the light source, and a photovoltaic cell1303, which light-absorbing surface of the photovoltaic cell is adjacentto the phosphorescent material. The photovoltaic cell can dischargepower to an electrical load 1309 when the electrical load is inelectrical communication with the photovoltaic cell. The photovoltaiccell can discharge power to a rechargeable battery 1308 when theelectrical load is not in electrical communication with the photovoltaiccell.

For example, a circuitry of the photon battery assembly 1300 cancomprise a switch 1310 that either completes a first electric path 1312or a second electric path 1313. In some cases, the switch can completeneither electric path (e.g., as shown in FIG. 13), and when neitherelectric path is completed, the power generated by the photon batteryassembly can be wasted or lost from the energy storage system. The firstelectric path 1312 can be completed when no electrical load (e.g.,electrical load 1309) is connected to the photon battery assembly 1300.In some instances, completing the first electric path 1312 can be thedefault state of the switch 1310. When no electrical load is connected,the first electric path can be completed, thus directing the powergenerated by the photovoltaic cell 1303, such as through a port 1306 ofthe photovoltaic cell, to the rechargeable battery 1308. Therechargeable battery can store the energy received from the photovoltaiccell. The rechargeable battery can discharge its own electrical power,such as to another electrical load, and/or back to the photon batteryassembly 1300, such as through a second port 1307 of the light source1301. In some instances, the second port 1307 and the first port 1305 ofthe light source can be the same port.

The second electric path 1313 can be completed when at least oneelectrical load (e.g., electrical load 1309) is connected to the photonbattery assembly 1300. In some instances, connecting an electrical loadto the photon battery assembly can trigger the switch 1310 to alternatefrom a default path (or from completing a different electrical path) tocompleting the second electric path 1313. When an electrical load 1309is connected, the second electric path can be completed, thus directingthe power generated by the photovoltaic cell 1303, such as through theport 1306, to the electrical load 1309.

In some cases, the first electric path 1312 and the second electric path1313 can be mutually exclusive. In some cases, a circuit can connect theport 1306 of the photovoltaic cell 1303, the rechargeable battery 1308,and the electrical load 1309 in series or in parallel andsimultaneously, or discretely, direct at least some power to therechargeable battery and direct at least some power to the electricalload.

Alternatively or in addition, a circuitry of the photon battery assembly1300 can comprise a switch 1311 that either completes a third electricpath 1314 or a fourth electric path 1315. In some cases, the switch cancomplete neither electric path (e.g., as shown in FIG. 13), and whenneither electric path is completed, the power generated by the photonbattery assembly can be wasted or lost from the energy storage system.In some instances, completing the third electric path 1314 can be thedefault state of the switch 1311. When the third electric path iscompleted, power generated by the rechargeable battery 1308 can bedirected to the photon battery assembly 1300, such as through the secondport 1307 of the light source 1301. In some instances, the second port1307 and the first port 1305 of the light source can be the same port.When the fourth electric path 1315 is completed, the power generated bythe photovoltaic cell 1303, such as through the port 1306, can bedirected back to the photon battery assembly 1300, such as through thesecond port 1307 of the light source 501.

In some cases, the first electric path 1312, the second electric path1313, the third electric path 1314, and the fourth electric path 1315can be mutually exclusive. In some cases, a circuit can connect the port1306 of the photovoltaic cell 1303, the rechargeable battery 1308, theelectrical load 1309, the second port 1307 of the light source 1301, orany combination thereof in series or in parallel and simultaneously, ordiscretely, direct at least some power to or from different components.

In some cases, the circuitry can be controlled manually (e.g., manualconnection of electrical load to photon battery assembly, such aspushing in a cable, nudges a switch component into a circuit position).Alternatively or in addition, the circuitry can be controlled by acontroller (not shown in FIG. 13). The controller may be capable ofsensing the connection(s) of one or more electrical loads with thephoton battery assembly. The controller may be capable of sensing theconnection(s) of one or more rechargeable batteries with the photonbattery assembly and/or the one or more electrical loads. The controllermay be capable of completing different electrical circuit paths (e.g.,first electric path 1312, second electric path 1313, third electric path1314, fourth electric path 1315, etc.), such as via controlling one ormore switch components (e.g., switch 1310, switch 1311, etc.) or otherelectrical components.

FIG. 14 shows a stack of a plurality of photon battery assemblies. Aphoton battery assembly can be connected to achieve different desiredvoltages, energy storage capacities, power densities, and/or otherbattery properties. For example, an energy storage system 1400 comprisesa stack of a first photon battery assembly 1401, a second photon batteryassembly 1402, a third photon battery assembly 1401, and a fourth photonbattery assembly 1401. The first photon battery assembly can compriseits own light source 1401A, phosphorescent material 1401B, andphotovoltaic cell 1401C. Similarly, the second photon battery assemblycan comprise its own light source 1402A, phosphorescent material 1402B,and photovoltaic cell 1402C. Similarly, the third photon batteryassembly can comprise its own light source 1403A, phosphorescentmaterial 1403B, and photovoltaic cell 1403C. Similarly, the fourthphoton battery assembly can comprise its own light source 1404A,phosphorescent material 1404B, and photovoltaic cell 1404C. While FIG.14 shows four photon battery assemblies stacked together, any number ofphoton battery assemblies can be stacked together. For example, at least2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 100, 200, ormore photon battery assemblies can be stacked together.

Each photon battery assembly can be configured as described in FIGS. 1-3and 12-13. Alternatively, different components of the photon batteryassembly (e.g., light source, phosphorescent material, photovoltaiccell) can be stacked in different configurations (e.g., orders) suchthat any phosphorescent material layer is adjacent to both a lightsource layer and a photovoltaic cell layer. For example, a firstphotovoltaic cell layer can be adjacent to a first phosphorescentmaterial layer, which is also adjacent to a light source layer, which isalso adjacent to a second phosphorescent material layer, which is alsoadjacent to a second photovoltaic cell layer. As in the example above, aphosphorescent material layer can act as intermediary layers betweenalternating layers of the photovoltaic cell and the light source. Forexample, a light source can have at least two light-emitting surfacesthat are each in optical communication with distinct phosphorescentmaterials (e.g., different volumes of phosphorescent materials). Forexample, a photovoltaic cell can have at least two light-absorbingsurfaces that are each in optical communication with distinctphosphorescent materials (e.g., different volumes of phosphorescentmaterials).

A plurality of photon battery assemblies can be electrically connectedin series, in parallel, or a combination thereof. While FIG. 14 shows avertical stack, the assemblies can be stacked in differentconfigurations, such as in horizontal stacks on in concentric (orcircular) stacks. In some instances, there may be interconnects and/orother electrical components between each photon battery assembly. Insome instances, a controller can be electrically coupled to one or morephoton battery assemblies (e.g., 1401, 1402, 1403, 1404, etc.) and becapable of managing the inflow and/or outflow of power from each or acombination of the battery assemblies.

As described elsewhere herein, photovoltaic cells in a photon batteryassembly generate electrical power by absorbing optical energy from thephosphorescent material. However, if the phosphorescent material is toothick in depth, the optical energy emitted by the phosphorescentmaterial may not be efficiently absorbed by the photovoltaic cell, duein part to other phosphorescent material obstructing optical paths toone or more light-absorbing surfaces of the photovoltaic cell. Forexample, the photons emitted by the outermost material (closest to theinterface between the light absorbing surface of the photovoltaic celland the phosphorescent material) of the phosphorescent material may beabsorbed with less resistance than the photons emitted by the innermaterial (farthest from the interface between the phosphorescentmaterial and the photovoltaic cell). Therefore, in some instances, itmay be beneficial to have a relatively thin layer of phosphorescentmaterial interfacing with a relatively large surface area of alight-absorbing surface of the photovoltaic cells. Provided herein aretrench-like configurations of the photon battery assembly that canincrease interfacial surface area between the phosphorescent materialand the photovoltaic cells, thus allowing for more efficient absorptionof optical energy by the photovoltaic cells.

FIG. 15 shows a cross-sectional side view of an exemplary trenchconfiguration of a photon battery assembly and FIG. 16 shows across-sectional top view of an exemplary trench configuration of aphoton battery assembly. FIG. 15 and FIG. 16 may or may not be differentviews of the same trench configuration of a photon battery.

Referring to FIG. 15, a photon battery assembly 1500 comprises a lightsource 1501 (e.g., LEDs), phosphorescent material 1502, and photovoltaiccells 1503. As described elsewhere herein, a light-emitting surface ofthe light source can be adjacent to the phosphorescent material, and alight absorbing surface of the photovoltaic cells can be adjacent to thephosphorescent material.

In some instances, the photovoltaic cells 1503 can comprise one or moredepressions defined by corresponding protrusions. The depressions and/orthe corresponding protrusions can be defined by the light-absorbingsurface of the photovoltaic cells. For example, the photovoltaic cellscan comprise one or more troughs and/or peaks. Alternatively or inaddition, the photovoltaic cells can comprise grooves, cuts, trenches,wells, and/or other characterizations of depressions. A depression canbe formed by etching, cutting, carving, digging, excavating, molding,pressurizing, and/or other mechanical methods. Alternatively or inaddition, a depression can be formed by constructing, building, and/orassembling the photovoltaic cells to comprise the depression.

In some instances, a depth 1505 of a depression 1504 may be 100 timeslonger than a maximum width 1505 (or diameter) of the depression 1504.In some instances, a depth of a depression may be at least 2, 3, 4, 5,6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100,150, 200, 300, 400, 500, 600, 700, 800, 900, 1000 or more times longerthan a maximum width of the depression. In some instances, a maximumwidth of a depression can be at least about 50 nanometers (nm), 60 nm,70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 200nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 millimeter(mm), 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm,1.9 mm, 2.0 mm or greater. Alternatively, the maximum width of adepression can be less than about 50 nm. In some instances, a depth of adepression can be at least about 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7mm, 8 mm, 9 mm, 1 centimeter (cm), or greater. Alternatively, the depthof a depression can be less than about 1 mm. In some instances, amaximum width of a depression may be substantially the same as a maximumwidth of a protrusion. Alternatively, a maximum width of a depressionmay be at least 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 20%, 30%, 40%,50%, 60%, 70%, 80%, 90%, 100%, 200%, 300%, 400%, 500%, 1000%, 2000%,3000%, 4000%, 5000% or more greater than a maximum width of aprotrusion. Alternatively, the maximum width of a depression may lessthan the maximum width of a protrusion. In some instances, thephotovoltaic cell 1503 can comprise at least about 1, 2, 3, 4, 5, 6, 7,8, 8, 10, 11, 12, 13, 14, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150,200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000, 3000, 4000, 5000,6000, 7000, 8000, 9000, 10,000, 20,0000, or more depressions percentimeter length of the photovoltaic cell. Alternatively, thephotovoltaic cell can comprise less than about 1 depression percentimeter length of the photovoltaic cell.

While FIG. 15 shows a certain number of depressions in the photovoltaiccell structure, the number of depressions in the photovoltaic cells isnot restricted as such. The phosphorescent material 1502 can interfacewith the significantly larger surface area of the light-absorbingsurfaces of the photovoltaic cell 1503 which define the depressionsand/or corresponding protrusions, at least when compared to the surfacearea of planar light-absorbing surfaces of the photovoltaic cell (suchas in FIG. 1).

In some embodiments, the photovoltaic cell 1503 may be contacting thelight source 1501 (not shown in FIG. 15). For example, one or morelight-emitting surfaces of the light source 1501 can cap or cover thedepressions (or wells) of the photovoltaic cell 1503 by contacting thetop (or peak) of the one or more protrusions defining the depressions.The light source can be in any configuration in which the phosphorescentmaterial 1502 is in optical communication with the light source. In someinstances, if the phosphorescent material is capable of absorbingnatural light, the light source may not be required in the assembly, andthe photon battery assembly 1500 can be in any configuration in whichthe phosphorescent material is in optical communication with a naturallight source (e.g., sunlight).

As described elsewhere herein, phosphorescent material 1502 in a photonbattery assembly 700 store energy over a finite duration of time byabsorbing optical energy at a first wavelength from a light source 1501and, after a time delay, emitting optical energy at a second wavelength,such as to photovoltaic cells 1503. However, if the phosphorescentmaterial is too thick in depth, the optical energy emitted by the lightsource may not be efficiently absorbed by the phosphorescent material,due in part to other phosphorescent material obstructing optical pathsfrom one or more light-emitting surfaces of the light source. Forexample, the photons emitted by the light source may be absorbed withless resistance by the outermost material (closest to the interfacebetween the light emitting surface of the light source and thephosphorescent material) of the phosphorescent material than by theinner material (farthest from the interface between the phosphorescentmaterial and the light source). Therefore, in some instances, it may bebeneficial to have a relatively thin layer of phosphorescent materialinterfacing with a relatively large surface area of a light-emittingsurface of the light source.

In some embodiments (not shown in FIG. 15), the light source 1501 maycomprise one or more depressions defined by corresponding protrusions.The depressions and/or corresponding protrusions can be defined bylight-emitting surfaces of the light source. For example, the lightsource can comprise one or more troughs and/or peaks. In some instances,a depth of a depression may be 100 times longer than a maximum width (ordiameter) of the depression. The phosphorescent material 1502 caninterface with the significantly larger surface area of thelight-emitting surfaces of the light source 1501 which define thedepressions and/or corresponding protrusions, at least when compared tothe surface area of planar light-emitting surfaces of the light source(such as in FIG. 1 and FIG. 15), thus allowing for more efficientabsorption of optical energy by the phosphorescent material.

In some embodiments (not shown in FIG. 15), both the light source 1501and the photovoltaic cells 1503 may comprise one or more depressionsdefined by corresponding protrusions. In some instances, the depressionsand/or corresponding protrusions defined by the light source can becomplementary to the depressions and/or corresponding protrusionsdefined by the photovoltaic cells. For example, a protrusion of thelight source may fit, with at least some room, within a depression ofthe photovoltaic cells, wherein the phosphorescent material lies withinthe at least some room between the light source and the photovoltaiccells. Alternatively or in addition, a protrusion of the photovoltaiccells may fit, with at least some room, within a depression of the lightsource, wherein the phosphorescent material lies within the at leastsome room between the light source and the photovoltaic cells.Beneficially, such configurations can increase the interfacial surfaceareas both between the phosphorescent material and the light source andbetween the phosphorescent material and the photovoltaic cells, thusallowing for more efficient absorption and emission of optical energy bythe phosphorescent material as well as efficient absorption of opticalenergy by the photovoltaic cells.

Referring to FIG. 16, a cross-sectional top view of a trenchconfiguration of a photon battery assembly is shown. A photon batteryassembly 1600 comprises a light source (not shown in FIG. 16),phosphorescent material 1602, and photovoltaic cells 1603. As describedelsewhere herein, a light-emitting surface of the light source can beadjacent to the phosphorescent material, and a light absorbing surfaceof the photovoltaic cells can be adjacent to the phosphorescentmaterial. The photovoltaic cell may comprise one or more depressionsthat go into the plane of FIG. 16 and one or more correspondingprotrusions that come out of the plane of FIG. 16. In some cases, adepression may be elongated in at least one dimension (that is not thedepth) and aligned in a horizontal or vertical array, such as is shownin FIG. 16. The depression may not be elongated. In some cases,depressions may be aligned in a grid having at least two axes (e.g.,horizontal and vertical axes, x and y axes) that may or may not be atright angles to each other.

Alternatively or in addition, the phosphorescent material may interfacewith a light-absorbing surface of the photovoltaic cell that has anyother shape, form, or structure, such as a planar structure (e.g., as inthe photovoltaic cell 103 shown in FIG. 1). The other shape, form, orstructure may increase interfacial surface area between thephosphorescent material and the photovoltaic cell than a planarstructure within the same reference volume. Alternatively or inaddition, the phosphorescent material may interface with alight-emitting surface of the light source that has any other shape,form, or structure, such as a planar structure (e.g., as in the lightsource 101 shown in FIG. 1). The other shape, form, or structure mayincrease interfacial surface area between the phosphorescent materialand the light source than a planar structure within the same referencevolume. Battery assemblies are described in U.S. Patent Pub. No.2018/0308601, which is entirely incorporated herein by reference for allpurposes.

FIG. 4A illustrates a photon battery assembly with a waveguide. A photonbattery assembly 400 can comprise a light source 401, a phosphorescentmaterial 402, a photovoltaic cell (not shown), and a waveguide 404. Thewaveguide may be adjacent to the light source and the phosphorescentmaterial. For example, the waveguide may be sandwiched by the lightsource and the phosphorescent material. In other examples, as shown inFIG. 4A, some surfaces of the waveguide may be adjacent to thephosphorescent material and some surfaces of the waveguide may beadjacent to the light source. In some instances, additionally, thewaveguide may be adjacent to the photovoltaic cell. The configuration ofthe photon battery assembly with the waveguide is not limited to FIG.4A.

Regardless of contact between the phosphorescent material 402 andwaveguide 404, the phosphorescent material and the waveguide may be inoptical communication. Regardless of contact between the light source401 and waveguide, the light source and the waveguide may be in opticalcommunication. In some instances, regardless of contact between thephotovoltaic cell and waveguide, the photovoltaic cell and the waveguidemay be in optical communication.

The waveguide 404 may or may not be contacting the light source 401. Ifthe waveguide and the light source are in contact, the waveguide caninterface a light-emitting surface of the light source. The waveguideand the light source can be coupled or fastened together at theinterface, such as via a fastening mechanism. In some instances, asupport carrying the light source and/or a support carrying thewaveguide may be coupled or fastened together at the interface. Examplesof fastening mechanisms may include, but are not limited to,form-fitting pairs, hooks and loops, latches, staples, clips, clamps,prongs, rings, brads, rubber bands, rivets, grommets, pins, ties, snaps,velcro, adhesives, tapes, a combination thereof, or any other types offastening mechanisms. In some instances, the waveguide may have adhesiveand/or cohesive properties and adhere to the light source without anindependent fastening mechanism. The waveguide and the light source canbe permanently or detachably fastened together. For example, thewaveguide and the light source can be disassembled from and reassembledinto the photon battery assembly 400 without damage (or with minimaldamage) to waveguide and/or the light source. Alternatively, while incontact, the waveguide and the light source may not be fastenedtogether.

If the waveguide 404 and the light source 401 are not in contact, thewaveguide can otherwise be in optical communication with alight-emitting surface of the light source. For example, the waveguidecan be positioned in an optical path of light emitted by thelight-emitting surface of the light source. In some instances, there canbe an air gap between the waveguide and the light source. In someinstances, there can be another intermediary layer, such as a solidmaterial (e.g., glass, plastic, etc.) and/or another waveguide, betweenthe waveguide and the light source. The intermediary layer can be airand/or other fluid. The intermediary layer can be a light guide oranother layer of optical elements (e.g., lens, reflector, diffusor, beamsplitter, etc.). In some instances, there can be a plurality ofintermediary layers between the waveguide and the light source. In someinstances, the waveguide may be in optical communication with one ormore surfaces of the waveguide. For example, the light source maycomprise an array and/or row of LEDs that are in optical communicationwith one or more surfaces of the waveguide. The waveguide may receivelight from the light source from any surface. In some instances, asurface of the waveguide in optical communication with a surface of alight source may be parallel, perpendicular, or at any angle whether indirect contact or not in contact. Either or both surfaces may be flat.Either or both surfaces may be angled and/or have a curvature (e.g.,convex, concave). Either or both surfaces may have any surface profile.

The waveguide 404 may or may not be contacting the phosphorescentmaterial 402. If the waveguide and the phosphorescent material are incontact, the waveguide can interface a light-absorbing surface of thephosphorescent material. The waveguide and the phosphorescent materialcan be coupled or fastened together at the interface, such as via afastening mechanism. In some instances, a support carrying thephosphorescent material and/or a support carrying the waveguide may becoupled or fastened together at the interface. Examples of fasteningmechanisms may include, but are not limited to, form-fitting pairs,hooks and loops, latches, staples, clips, clamps, prongs, rings, brads,rubber bands, rivets, grommets, pins, ties, snaps, velcro, adhesives,tapes, a combination thereof, or any other types of fasteningmechanisms. In some instances, the waveguide may have adhesive and/orcohesive properties and adhere to the phosphorescent material without anindependent fastening mechanism. In some instances, the phosphorescentmaterial may have adhesive and/or cohesive properties and adhere to thewaveguide without an independent fastening mechanism. For example, thephosphorescent material may be painted or coated on a light-emittingsurface of the waveguide. The waveguide and the phosphorescent materialcan be permanently or detachably fastened together. For example, thewaveguide and the phosphorescent material can be disassembled from andreassembled into the photon battery assembly 400 without damage (or withminimal damage) to waveguide and/or the phosphorescent material.Alternatively, while in contact, the waveguide and the phosphorescentmaterial may not be fastened together.

If the waveguide 404 and the phosphorescent material 402 are not incontact, the waveguide can otherwise be in optical communication with alight-absorbing surface of the phosphorescent material. For example, thephosphorescent material can be positioned in an optical path of lightemitted by the light-emitting surface of the waveguide. In someinstances, there can be an air gap between the waveguide and thephosphorescent material. In some instances, there can be anotherintermediary layer, such as another waveguide, between the waveguide andthe phosphorescent material. The intermediary layer can be air or otherfluid. The intermediary layer can be a light guide or another layer ofoptical elements (e.g., lens, reflector, diffusor, beam splitter, etc.).In some instances, there can be a plurality of intermediary layersbetween the waveguide and the phosphorescent material. In someinstances, the waveguide may be in optical communication with one ormore surfaces of the phosphorescent material. The phosphorescentmaterial may receive light from the waveguide from any surface. In someinstances, a surface of the waveguide in optical communication with asurface of a phosphorescent material may be parallel, perpendicular, orat any angle, whether in direct contact or not in contact. Either orboth surfaces may be flat. Either or both surfaces may be angled and/orhave a curvature (e.g., convex, concave). Either or both surfaces mayhave any surface profile.

The waveguide 404 may be configured to direct waves at a firstwavelength emitted from the light source 401 to the phosphorescentmaterial 402. Beneficially, the waveguide may deliver optical energyfrom the light source to the phosphorescent material with greatefficiency and minimal loss of optical energy (or other forms ofenergy). The waveguide may provide optical communication between thelight source and distributed volumes of the phosphorescent materialwhere otherwise some volumes of phosphorescent material would not be inoptical communication with the light source, allowing for flexiblearrangements of the light source relative to the phosphorescentmaterial. For example, without waveguides, the optical energy at thefirst wavelength emitted from the light source may be absorbed mostefficiently by the immediately adjacent volume of phosphorescentmaterial (relative to the light source or otherwise in immediate opticalcommunication with the light source), such as at the phosphorescentmaterial-light source interface. However, once such immediately adjacentphosphorescent material absorbs the optical energy at the firstwavelength, it may no longer have capacity to receive further opticalenergy and/or prevent other volumes of phosphorescent material (furtherdownstream in the optical path) from absorbing such optical energy.While large surface area interface between the phosphorescent materialand the light source may facilitate efficient optical energy deliveryfrom the light source to the phosphorescent material, this may beimpractical when constructing compact energy storage systems. Byimplementing waveguides to facilitate optical communication between thelight source and the phosphorescent material, different volumes of thephosphorescent material may evenly absorb the optical energy from thelight source even if such phosphorescent material and the light sourceare not immediately adjacent.

The waveguide 404 may have a maximum dimension (e.g., width, length,height, radius, diameter, etc.) of at least about 10 micrometers, 20micrometers, 30 micrometers, 40 micrometers, 50 micrometers, 60micrometers, 70 micrometers, 80 micrometers, 90 micrometers, 100micrometers, 200 micrometers, 300 micrometers, 400 micrometers, 500micrometers, 600 micrometers, 700 micrometers, 800 micrometers, 900micrometers, 1 millimeter (mm), 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8mm, 9 mm, 1 centimeter (cm), 2 cm, 3 cm, 4 cm, 5 cm, 10 cm, 15 cm, 20cm, 30 cm, 40 cm, 50 cm or more. Alternatively or in addition, thewaveguide may have a maximum dimension of at most about 50 cm, 40 cm, 30cm, 20 cm, 15 cm, 10 cm, 5 cm, 4 cm, 3 cm, 2 cm, 1 cm, 9 mm, 8 mm, 7 mm,6 mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, 900 micrometers, 800 micrometers,700 micrometers, 600 micrometers, 500 micrometers, 400 micrometers, 300micrometers, 200 micrometers, 100 micrometers, 90 micrometers, 80micrometers, 70 micrometers, 60 micrometers, 50 micrometers, 40micrometers, 30 micrometers, 20 micrometers, 10 micrometers, or less.The waveguide may be square, rectangular (e.g., having an aspect ratiofor length to width of about 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6,1:1.7, 1:1.8, 1:1.9, 1:2, 1:3, 1:4, 1:5, 1:10, etc.), or any othershape. The waveguide may comprise material such as plastic or glass. Thewaveguide may comprise material used in an injection mold.

For example, in FIG. 4A, the optical energy emitted from the lightsource 401 is directed through the layer of waveguide 404 to reachvarious locations of the phosphorescent material 402. As describedelsewhere herein, after a time delay, the phosphorescent material 402may emit optical energy at the second wavelength for absorption by aphotovoltaic cell (not shown). The waveguide may comprise one or morereflective surfaces 405 to direct waves from the light source to thephosphorescent material. The one or more reflective surfaces may haveincreasingly large reflective surfaces in the optical path within thewaveguide to allow some waves to be reflected at a first reflectivesurface for excitation of a first volume of phosphorescent material, andsome waves to travel further before being reflected at a secondreflective surface for excitation of a second volume of phosphorescentmaterial that is further from the light source than the first volume,and some waves to travel further before being reflected at a thirdreflective surface for excitation of a third volume of phosphorescentmaterial that is further than the second volume, and so on. There may beany number of reflective surfaces in the waveguide. For example, theremay be at least about 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70,80, 90, 100, 200, 300, 400, 500, or more reflective surfaces.Alternatively or in addition, a single reflective surface may graduallyincrease surface area, such as in a conical shape, in the optical pathwithin the waveguide to achieve a similar outcome.

In some instances, the waveguide may be adjacent to the phosphorescentmaterial from a first surface, and adjacent to the light source from asecond surface, wherein the first surface and the second surface aresubstantially orthogonal. The one or more reflective surfaces may beconfigured to direct waves in a substantially orthogonal direction suchas to receive from the light source from the second surface and totransmit through the first surface. Alternatively or in addition, thefirst surface and the second surface may be at any other angle and theone or more reflective surfaces may be configured to direct waves in theother angle, such as to receive from the light source from the secondsurface and to transmit through the first surface. As illustrated inFIG. 4A, the waveguide may be adjacent to a plurality of layers ofphosphorescent material (e.g., interfacing different surfaces of thewaveguide). The one or more reflective surfaces may be configured todirect waves received from the light source to the plurality of layersof phosphorescent material by reflecting the waves (e.g., light) to theplurality of layers.

In some instances, alternative to or in addition to the light source401, the photon battery assembly 400 may be charged (or thephosphorescent material excited) wirelessly. In some embodiments, aphoton battery assembly can comprise the phosphorescent material 402, aphotovoltaic cell (not shown), and the waveguide 404, without having thelight source 401 integrated in the assembly. For example, the lightsource 401 (illustrated in FIG. 4A) can be remote and detached from theother components. The light source may be driven by a power source thatis separate and/or detached from the photon battery assembly that itcharges. Such remote light source can be configured to provide opticalenergy to the assembly to achieve wireless charging of the assembly.Regardless of where the light source 401 is disposed with respect to theassembly and/or the waveguide, the light source may be in opticalcommunication with the waveguide and/or the phosphorescent material toprovide optical energy for excitation of the phosphorescent material.The remote light source can be configured to provide optical energy at ahigher energy level than the optical energy emitted by thephosphorescent material. For example, where the phosphorescent materialis strontium aluminate, the remote light source may provide opticalenergy at wavelengths that is shorter than the emission wavelength ofabout 520 nanometers. For example, the remote light source may providewaves at wavelengths between about 300 nanometers to about 470nanometers. The remote light source may provide such optical energy viaLED, lasers, or other optical beams, as described elsewhere herein. Insome instances, a photon battery assembly configuration may maximize (orotherwise) increase the exposed surface area of one or more waveguidesand/or the phosphorescent material to facilitate such wireless charging.Beneficially, the compactness and the transportability of the photonbattery assemblies described herein may be greatly increased by allowingfor wireless charging. Further, such wireless charging may allow forfast charging, optical charging, and on-demand charging, as well asbenefit from the general widespread availability of charging sources(e.g., availability of light sources). Any of the photon batteryassemblies may be configured for wireless charging, either in additionto wired (e.g., integrated) light source charging, or alternative tointegrated light source charging.

In some instances, the waveguide may be coated at one or more surfaces.Otherwise, the waveguide may be adjacent to and/or in contact withanother layer at one or more surfaces. For example, the waveguide may becoated at one or more surfaces that interfaces the phosphorescentmaterial 402. An example coating configuration is shown in FIG. 4B. Aphoton battery assembly can comprise a light source (not shown), aphosphorescent material 452, a photovoltaic cell 453, and a waveguide451, which has a coating 454 on one or more of its surfaces thatinterfaces the phosphorescent material. The waveguide may be adjacent tothe light source and the phosphorescent material, as described elsewhereherein.

The coating 454 may be disposed between the waveguide 451 and thephosphorescent material 452. In some instances, all surfaces of thewaveguide interfacing (or in optical communication with) thephosphorescent material may be covered by the coating. In otherinstances, a portion of the surfaces interfacing (or in opticalcommunication with) the phosphorescent material may be covered by thecoating and a portion of the surfaces interfacing (or in opticalcommunication with) the phosphorescent material may not be covered bythe coating. For example, such surfaces may be uncovered by anything andin direct optical communication with the phosphorescent material, or becovered by another coating or another layer (e.g., glass, anotherwaveguide, etc.) and be in optical communication with the phosphorescentmaterial through the other coating or other layer. In some instances,the other layer can be a light guide or another layer of opticalelements (e.g., lens, reflector, diffusor, beam splitter, etc.). In someinstances, there may be a plurality of layers between the waveguide 451and the phosphorescent material 452, including the coating 454. Forexample, the plurality of layers may include an air gap or other fluidgap, a solid layer (e.g., glass, plastic.), other optical elements(e.g., lens, reflector, diffusor, beam splitter, etc.), and/or any otherlayer, in any combination, and arranged in any order or sequence.Regardless of coating or waveguide configuration, the phosphorescentmaterial 452 and the waveguide 451 may be in optical communication.

The waveguide 404 may or may not be contacting the coating 454. Thewaveguide and the coating can be coupled or fastened together at theinterface, such as via a fastening mechanism. In some instances, asupport carrying the coating and/or a support carrying the waveguide maybe coupled or fastened together at the interface. Examples of fasteningmechanisms may include, but are not limited to, form-fitting pairs,hooks and loops, latches, staples, clips, clamps, prongs, rings, brads,rubber bands, rivets, grommets, pins, ties, snaps, velcro, adhesives,tapes, a combination thereof, or any other types of fasteningmechanisms. In some instances, the coating may have adhesive and/orcohesive properties and adhere to the waveguide without an independentfastening mechanism. In some instances, the waveguide may have adhesiveand/or cohesive properties and adhere to the coating without anindependent fastening mechanism. For example, the coating may be paintedor coated on a surface of the waveguide. The waveguide and the coatingcan be permanently or detachably fastened together. For example, thewaveguide and the coating can be disassembled from and reassembled intothe photon battery assembly without damage (or with minimal damage) towaveguide and/or the coating. Alternatively, while in contact, thewaveguide and the coating may not be fastened together.

The coating 454 may be a dichroic coating or comprise other opticalfilter(s). For example, the coating may be configured to allow waves atcertain first wavelength(s) (e.g., longer wavelength) in to excite thephosphorescent material 452, but reflect the waves at certain secondwavelength(s) (e.g., shorter wavelength). For example, waves with longerwavelength(s) may be allowed to reach the phosphorescent materialthrough the coating, and waves with shorter wavelengths(s) emitted bythe phosphorescent material may be reflected by the coating and keptwithin the phosphorescent material layer to (i) increase the likelihoodthat such waves with shorter wavelengths are incident upon thephotovoltaic cell 453, and (ii) prevent such waves from entering thewaveguide 451 and generating undesired heat.

The coating 454 may have any thickness. For example, the coating may bebetween 0.5 micrometers and 5 micrometers. In some instances, thecoating may be at least about 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2,1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6,2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0,4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0 micrometers or more inthickness. Alternatively or in addition, the coating may be at mostabout 5.0, 4.9, 4.8, 4.7, 4.6, 4.5, 4.4, 4.3, 4.2, 4.1, 4.0, 3.9, 3.8,3.7, 3.6, 3.5, 3.4, 3.3, 3.2, 3.1, 3.0, 2.9, 2.8, 2.7, 2.6, 2.5, 2.4,2.3, 2.2, 2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0,0.9, 0.8, 0.7, 0.6, 0.5 micrometers or less in thickness.

Alternatively or in addition to the coating 454, the waveguide 451 maycomprise a surface feature 455 (or multiple features) to facilitate thedirection of waves towards a certain direction, and/or increase theuniformity of the direction in which waves are directed. For example,one or more surfaces of the waveguide may comprise physical structuresor features, such as grooves, troughs, indentations, hills, pillars,walls, and/or other structures or features. In an example, a bottomsurface of the waveguide may comprise one or more grooves formed inwardsthe waveguide such that waves from the light source are uniformlyreflected in a direction towards the phosphorescent material to excitethe phosphorescent material. Such grooves (and/or other physicalstructures or features) may be patterned into the waveguide. Thepatterns may be regular or irregular. For example, the grooves may bespaced at regular intervals or irregularly spaced. In some instances,such grooves (and/or other physical structures or features) may bediscrete features. The physical structure or feature may be formed byany mechanism, such as mechanical machining. In some instances, diamondturning can be used to etch or cut the physical structures or features(e.g., grooves) into the waveguide. In some instances, one or morephysical features may be integral to the waveguide. In some instances,one or more physical features may be external to, and/or otherwisecoupled/attached to the waveguide by any fastening mechanism describedelsewhere herein. Alternatively or in addition to the coating 454 and/orthe surface feature 455, the waveguide 451 may further comprise surfacemarking to facilitate the direction of waves towards a certaindirection. For example, one or more surfaces of the waveguide maycomprise painted markings having certain optical properties thatfacilitating the scattering of waves in a certain direction. Forexample, such painted markings may be white painted dots that facilitatescatter of light towards the phosphorescent material to excite thephosphorescent material. The waveguide may comprise any number of suchpainted dots (or other surface markings). The waveguide may comprise anytype of painted markings, including other colored dots. The markings mayform a pattern. The patterns may be regular or irregular. For example,the dots may be spaced at regular intervals or irregularly spaced. Insome instances, such dots may be discrete markings.

Any of the photon battery assemblies described herein may comprise awaveguide in optical communication with an optical filter, such as thedichroic coating described with respect to FIG. 4B, or comprise awaveguide comprising the physical features and/or markings describedwith respect to FIG. 4B. For example, the photon battery assembly 100 ofFIG. 1 may comprise a waveguide (not shown) in optical communicationwith a coating disposed between the waveguide and the phosphorescentmaterial 102. For example, the photon battery assembly 400 of FIG. 4Amay comprise a coating disposed between the waveguide 404 and thephosphorescent material 402. 661 FIG. 5 illustrates another photonbattery assembly with a waveguide. A photon battery assembly 500 cancomprise a light source (not shown), a phosphorescent material 502, aphotovoltaic cell 503, and a waveguide 506. The waveguide may beadjacent to the photovoltaic cell and the phosphorescent material. Forexample, the waveguide may be sandwiched by the photovoltaic cell andthe phosphorescent material. In other examples, as shown in FIG. 5, somesurfaces of the waveguide may be adjacent to the phosphorescent materialand some surfaces of the waveguide may be adjacent to the photovoltaiccell. In some instances, additionally, the waveguide may be adjacent tothe light source. The configuration of the photon battery assembly withthe waveguide is not limited to FIG. 5.

Regardless of contact between the phosphorescent material 502 andwaveguide 506, the phosphorescent material and the waveguide may be inoptical communication. Regardless of contact between the photovoltaiccell 503 and waveguide, the photovoltaic cell and the waveguide may bein optical communication. In some instances, regardless of contactbetween the light source and waveguide, the light source and thewaveguide may be in optical communication.

The waveguide 506 may or may not be contacting the photovoltaic cell503. If the waveguide and the photovoltaic cell are in contact, thewaveguide can interface a light-absorbing surface of the photovoltaiccell. The waveguide and the photovoltaic cell can be coupled or fastenedtogether at the interface, such as via a fastening mechanism. In someinstances, a support carrying the photovoltaic cell and/or a supportcarrying the waveguide may be coupled or fastened together at theinterface. Examples of fastening mechanisms may include, but are notlimited to, form-fitting pairs, hooks and loops, latches, staples,clips, clamps, prongs, rings, brads, rubber bands, rivets, grommets,pins, ties, snaps, velcro, adhesives, tapes, a combination thereof, orany other types of fastening mechanisms. In some instances, thewaveguide may have adhesive and/or cohesive properties and adhere to thephotovoltaic cell without an independent fastening mechanism. Thewaveguide and the photovoltaic cell can be permanently or detachablyfastened together. For example, the waveguide and the photovoltaic cellcan be disassembled from and reassembled into the photon batteryassembly 500 without damage (or with minimal damage) to waveguide and/orthe photovoltaic cell. Alternatively, while in contact, the waveguideand the photovoltaic cell may not be fastened together.

If the waveguide 506 and the photovoltaic cell 503 are not in contact,the waveguide can otherwise be in optical communication with alight-emitting surface of the photovoltaic cell. For example, thephotovoltaic cell can be positioned in an optical path of light emittedby a light-emitting surface of the waveguide. In some instances, therecan be an air gap between the waveguide and the photovoltaic cell. Insome instances, there can be another intermediary layer, such as anotherwaveguide, between the waveguide and the photovoltaic cell. Theintermediary layer can be air or other fluid. The intermediary layer canbe a light guide or another layer of optical elements (e.g., lens,reflector, diffusor, beam splitter, etc.). In some instances, there canbe a plurality of intermediary layers between the waveguide and thephotovoltaic cell.

The waveguide 506 may or may not be contacting the phosphorescentmaterial 502. If the waveguide and the phosphorescent material are incontact, the waveguide can interface a light-emitting surface of thephosphorescent material. The waveguide and the phosphorescent materialcan be coupled or fastened together at the interface, such as via afastening mechanism. In some instances, a support carrying thephosphorescent material and/or a support carrying the waveguide may becoupled or fastened together at the interface. Examples of fasteningmechanisms may include, but are not limited to, form-fitting pairs,hooks and loops, latches, staples, clips, clamps, prongs, rings, brads,rubber bands, rivets, grommets, pins, ties, snaps, velcro, adhesives,tapes, a combination thereof, or any other types of fasteningmechanisms. In some instances, the waveguide may have adhesive and/orcohesive properties and adhere to the phosphorescent material without anindependent fastening mechanism. In some instances, the phosphorescentmaterial may have adhesive and/or cohesive properties and adhere to thewaveguide without an independent fastening mechanism. For example, thephosphorescent material may be painted or coated on the waveguide. Thewaveguide and the phosphorescent material can be permanently ordetachably fastened together. For example, the waveguide and thephosphorescent material can be disassembled from and reassembled intothe photon battery assembly 500 without damage (or with minimal damage)to waveguide and/or the phosphorescent material. Alternatively, while incontact, the waveguide and the phosphorescent material may not befastened together.

If the waveguide 506 and the phosphorescent material 502 are not incontact, the waveguide can otherwise be in optical communication with alight-emitting surface of the phosphorescent material. In someinstances, there can be another intermediary layer, such as anotherwaveguide, between the waveguide and the phosphorescent material. Theintermediary layer can be air or other fluid. The intermediary layer canbe a light guide or another layer of optical elements (e.g., lens,reflector, diffusor, beam splitter, etc.). In some instances, there canbe a plurality of intermediary layers between the waveguide and thephosphorescent material.

The waveguide 506 may be configured to direct waves at a secondwavelength emitted from the phosphorescent material 502 to thephotovoltaic cell 503. Beneficially, the waveguide may deliver opticalenergy from the phosphorescent material to the photovoltaic cell withgreat efficiency and minimal loss of optical energy (or other forms ofenergy). The phosphorescent material may emit optical energy at thesecond wavelength without directional specificity, such as in isotropicemission. The waveguide may provide optical communication between thephotovoltaic cell and distributed volumes of the phosphorescent materialwhere otherwise some volumes of phosphorescent material would not be inoptical communication with the photovoltaic cell, allowing for flexiblearrangements of the photovoltaic cell relative to the phosphorescentmaterial. For example, without waveguides, the optical energy at thesecond wavelength emitted from the phosphorescent material may beabsorbed most efficiently by the immediately adjacent light absorbingsurface of the photovoltaic cell, if it reaches the photovoltaic cell atall. The optical energy that is emitted away from the light absorbingsurface of the photovoltaic cell may be lost in the process. While largesurface area interface between the phosphorescent material and thephotovoltaic cell may facilitate efficient optical energy delivery fromthe phosphorescent material to the photovoltaic cell, this may beimpractical and expensive when constructing compact energy storagesystems. By implementing waveguides to facilitate optical communicationbetween the photovoltaic cell and the phosphorescent material, thephotovoltaic cell may efficiently absorb the optical energy from thephosphorescent material even if they are not immediately adjacent.

The waveguide 506 may have a maximum dimension (e.g., width, length,height, radius, diameter, etc.) of at least about 1 millimeter (mm), 2mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 1 centimeter (cm), 2 cm, 3cm, 4 cm, 5 cm, 10 cm, 15 cm, 20 cm, 30 cm, 40 cm, 50 cm or more.Alternatively or in addition, the waveguide may have a maximum dimensionof at most about 50 cm, 40 cm, 30 cm, 20 cm, 15 cm, 10 cm, 5 cm, 4 cm, 3cm, 2 cm, 1 cm, 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm orless. The waveguide may be square, rectangular (e.g., having an aspectratio for length to width of about 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5,1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:3, 1:4, 1:5, 1:10, etc.), or anyother shape. The waveguide may comprise material such as plastic orglass. The waveguide may comprise material used in an injection mold.

For example, in FIG. 5, the optical energy emitted from thephosphorescent material 502 is directed through the layer of waveguide506 to reach the photovoltaic cell 503. As described elsewhere herein,the phosphorescent material 502 may have absorbed optical energy at thefirst wavelength from a light source (not shown), such as in theconfiguration illustrated in FIG. 4A. The waveguide 506 may have arefractive index such as to allow for total internal reflection of theoptical wave at the second wavelength within the waveguide 506 untilsuch optical energy is transmitted to the photovoltaic cell 503. Thewaveguide may have a lower refractive index than any adjacent layer tothe waveguide. In some instances, the waveguide may be adjacent to thephosphorescent material from a first surface, and adjacent to thephotovoltaic cell from a second surface, wherein the first surface andthe second surface are substantially orthogonal. In some instances, thewaveguide may be adjacent to a plurality of layers of phosphorescentmaterial (e.g., interfacing different surfaces of the waveguide), andconfigured to direct waves received from the plurality of layers ofphosphorescent material to the photovoltaic cell.

FIG. 6 illustrates another photon battery assembly with waveguides. Aphoton battery assembly 600 can comprise a light source 601, aphosphorescent material 602, a photovoltaic cell 603, a first waveguide604, and a second waveguide 606. In some instances, the first waveguide604 may correspond to the waveguide 404 described with respect to FIG.4. In some instances, the second waveguide 606 may correspond to thewaveguide 506 described with respect to FIG. 5.

The photon battery assembly 600 may be constructed such that the firstwaveguide 604 is adjacent to the second waveguide 606, and the secondwaveguide is adjacent to the phosphorescent material 602. The firstwaveguide and the phosphorescent material may each be adjacent to twosurfaces of the second waveguide that are substantially parallel. Thefirst waveguide may be adjacent to the light source 601. The lightsource and the second waveguide may be adjacent to two surfaces of thefirst waveguide that are substantially orthogonal. The second waveguidemay be adjacent to the photovoltaic cell 603. The photovoltaic cell andthe phosphorescent material may be adjacent to two surface of the secondwaveguide that are substantially orthogonal. In some instances, thephotovoltaic cell and the light source may be substantially paralleland/or coplanar. The configuration of the photon battery assembly withwaveguides is not limited to FIG. 6.

In operation, the photon battery may be charged via the first waveguide604 which guides optical energy emitted by the light source 601 at thefirst wavelength to the phosphorescent material 602. The optical energyreceived from the light source may be substantially orthogonallyreflected (e.g., via a reflective surface) within the first waveguide topass through the second waveguide 606 (with minimal energy loss) foreven absorption across the phosphorescent material and subsequentexcitation. After a time delay, as described elsewhere herein, thephosphorescent material may emit optical energy at a second wavelength.Such emission may be isotropic (e.g., non-direction specific). Theemitted optical energy may be directed by the second waveguide, such asvia total internal reflection, to the photovoltaic cell for absorptionby the photovoltaic cell. Alternatively or in addition, the emittedoptical energy may be directed to the photovoltaic cell directly. Insome instances, the second waveguide may have a refractive index that islower than that of the first waveguide and that of the phosphorescentmaterial to allow for total internal reflection. As illustrated in FIG.6, the photon battery may be stacked in a similar configuration.

FIG. 7 shows a stack of a plurality of photon battery assemblies. Aphoton battery assembly can be connected to achieve different desiredvoltages, energy storage capacities, power densities, and/or otherbattery properties. For example, an energy storage system 700 maycomprise a stack of a first photon battery assembly, a second photonbattery assembly, a third photon battery assembly, a fourth photonbattery assembly, and so on, which are stacked vertically orhorizontally. Each photon battery assembly may comprise (or share) alight source, phosphorescent material, photovoltaic cell, firstwaveguide, and second waveguide, as described elsewhere herein. WhileFIG. 7 shows six photon battery assemblies stacked together, any numberof photon battery assemblies can be stacked together in anyconfiguration. For example, at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20,25, 30, 35, 40, 45, 50, 100, 200, or more photon battery assemblies canbe stacked together. While FIG. 7 shows a linear grid-like stack in thehorizontal and vertical directions, the assemblies can be stacked indifferent configurations, such as in concentric (or circular) stacks.

FIG. 8 shows an exploded view of another configuration for a photonbattery assembly stack with hollow core waveguides. A waveguide 806 maycomprise a hollow core. For example, the waveguide may be an opticalfiber or cable with a hollow core. Alternatively, the waveguide may havea cavity or trench with an opening. The waveguide may have a pluralityof cavities or trenches with a plurality of openings. The hollow core(or cavity or trench) may be filled by phosphorescent material 802 suchas to form filled cylindrical units. Alternatively, the hollow core maybe any shape (e.g., rectangular, triangular, hexagonal, non-polygonal,etc.). The cylindrical units may be linearly stacked, such as in groupsof 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 100, 200, or more units.The groups of linearly stacked cylindrical units may be sandwiched onopposing sides by light source panels 801. In some instances, a singlelight source panel may stretch along a length of a cylindrical unit.Alternatively, as shown in FIG. 8, a plurality of light source panelsmay be intermittently placed along the length of the single cylindricalunit. In some instances, groups of linearly stacked cylindrical unitsand the sandwiching light source panels may be stacked in alternatinglayers. Although this example shows four groups of six linearly stackedcylindrical units alternating with five light source panels for eachunit length of cylindrical unit, the stack may be in any configuration(e.g., 25 groups of 7 linearly stacked cylindrical units alternatingwith 26 light source panels). A photovoltaic cell 803 may be adjacent tothe end of the cylindrical units, substantially orthogonal to thelengths of the cylindrical units, and substantially orthogonal to thelight source panels. The photon battery assembly may resemble a cuboidshape, as illustrated in FIG. 8. The photon battery assembly is notlimited to the configuration illustrated in FIGS. 8.

In some instances, the light source panel 801 may comprise a lightsource (e.g., LED) and a waveguide. The waveguide may correspond to thewaveguide 404 described with respect to FIG. 4 and configured to directoptical energy from the light source to different cylindrical units.FIG. 9 illustrates a partial cross-sectional side view of the photonbattery assembly stack of FIG. 8. The optical energy emitted by a lightsource 901 is directed by one or more reflective surfaces 905 in a firstwaveguide (e.g., in the light source panel 801) to the phosphorescentmaterial 902 in different cylindrical units. The optical energy may passthrough a second waveguide 906 (configured to direct optical energyemitted from the phosphorescent material to the photovoltaic cell (notshown)). The first waveguide may comprise increasingly larger reflectivesurfaces (e.g., 905) in the direction of the optical path of the opticalenergy emitted by the light source 901 such as to evenly distribute theoptical energy to the different cylindrical units (e.g., in the linearstack).

Each photon battery assembly can be configured as described in FIGS.1-9. Alternatively, different components of the photon battery assembly(e.g., light source, phosphorescent material, photovoltaic cell, firstwaveguide, second waveguide, coating, etc.) can be stacked in differentconfigurations (e.g., orders). A plurality of photon battery assembliescan be electrically connected in series, in parallel, or a combinationthereof. In some instances, there may be interconnects and/or otherelectrical components between each photon battery assembly. In someinstances, a controller can be electrically coupled to one or morephoton battery assemblies and be capable of managing the inflow and/oroutflow of power from each or a combination of the battery assemblies.

In some embodiments, alternative to or in addition to the opticalenergy, the phosphorescent material may absorb kinetic energy, and aftera time delay, emit optical energy converted from the kinetic energy tobe absorbed by the photovoltaic cell. For example, radioactive materialcan excite the phosphorescent material with high energy particles(having high kinetic energy).

FIG. 17 shows a photon battery assembly comprising radioactive material.The photon battery assembly 1700 can comprise radioactive material 1701,phosphorescent material 1702, and photovoltaic cells 1703. In someinstances, the radioactive material 1701 can substitute the light sourcein previous embodiments of the photon battery assembly (e.g., lightsource in FIGS. 1-3 and FIGS. 12-16). In some instances, the radioactivematerial 1701 can be in addition to the light source in previousembodiments (light source not shown in FIG. 17).

As described elsewhere herein, the phosphorescent material 1702 can beadjacent to a light-absorbing surface of the photovoltaic cell 1703. Insome instances, as described elsewhere herein (and as shown in FIG. 17),the phosphorescent material may interface with a light-absorbing surfaceof the photovoltaic cell 1703 that defines one or more depressionsand/or corresponding protrusions. In other instances, the phosphorescentmaterial may interface with a light-absorbing surface of thephotovoltaic cell that has any other shape, form, or structure, such asa planar structure (e.g., as in the photovoltaic cell 103 shown in FIG.1). The phosphorescent material may further be adjacent to theradioactive material 1701. For example, the phosphorescent material canbe adjacent to a high energy particle emitting surface of theradioactive material. In some instances, the radioactive material may beshielded from the rest of the photon battery assembly (e.g.,phosphorescent material, photovoltaic cell, etc.) in a shell, casing,membrane, or other compartment 1704. The compartment 1704 may allow highenergy particles (or otherwise kinetic energy) to permeate or passthrough the compartment to contact the phosphorescent material. In someinstances, relatively heavy elements such as lead can be used to reflectradioactive emission (e.g., high energy particles) towards thephosphorescent material.

While FIG. 17 shows the radioactive material 1701 positioned above boththe phosphorescent material 1702 and the photovoltaic cell 1703, theconfiguration of the photon battery assembly 1700 is not limited tosuch. For example, the radioactive material may be positioned in themiddle, the bottom, and/or in a location between the trench-likeconfigurations of the photovoltaic cell. In another example, theradioactive material may be positioned between at least a portion of thephotovoltaic cell and the phosphorescent material. In another example,the radioactive material may be in one or more different compartmentsand placed in different locations relative to the photovoltaic celland/or the phosphorescent material. The radioactive material may bepositioned in a location where high energy particles emitted by theradioactive material is capable of reaching and/or travelling throughthe phosphorescent material.

The radioactive material 1701 can emit high energy particles, such asproducts of radioactive decay. Radioactive decay can include alphadecay, beta decay, gamma decay, and/or spontaneous fission. The highenergy particles can be alpha particles (e.g., nucleons), beta decayproducts (e.g., electrons, positrons, neutrino, etc.), gamma rays,and/or a combination thereof. The high energy particles can have highkinetic energy. The high energy particles can travel through thephosphorescent material 1702 upon emission from the radioactive materialand excite the phosphorescent material (e.g., absorb the kinetic energyof the high energy particles). The phosphorescent material cansubsequently, after a time delay, emit optical energy, such as at avisible wavelength (e.g., 400-700 nm). In some instances, the rate ofabsorption of kinetic energy by the phosphorescent material can befaster than the rate of emission of optical energy by the phosphorescentmaterial. The phosphorescent material can emit optical energy at otherwavelengths or ranges of wavelengths in the electromagnetic spectrum. Asdescribed elsewhere herein, the photovoltaic cell 1703 can absorb suchoptical energy emitted by the phosphorescent material and generateelectrical power. The electrical power generated by the photovoltaiccell can be discharged to an electrical load 1707, such as through aport 1706 of the photovoltaic cell. In some instances, the photonbattery assembly 1700 can comprise an outer casing, shell or compartment1705 to house the radioactive material 1701, phosphorescent material1702, and the photovoltaic cells 1703, such as to contain any radiationthat can escape the energy storage system during normal use. Thecompartment 1705 can be configured to contain any radiation emitted bythe radioactive material 1701 from escaping the compartment 1705. Forexample, the port 1706 of the photovoltaic cell may be the onlyconnection from outside the compartment 1705 to inside the compartment1705.

For example, the radioactive material 1701 can be strontium-90. Otherexamples of radioactive material can include, but are not limited to,tritium, beryllium-10, carbon-14, fluorine-18, aluminium-26,chlorine-36, potassium-40, calcium-41, cobalt-60, technetium-99,technetium-99m, iodine-129, iodine-131, xenon-135, caesium-137,gadolinium-153, bismuth-209, polonium-210, radon-222, thorium-232,uranium-235, plutonium-238, plutonium-239, americium-241, andcalifornium-252.

FIG. 18 shows a photon battery assembly comprising radioactive materialin the phosphorescent material. In some instances, a photon batteryassembly 1800 may comprise a phosphorescent material 1801 that comprisesa radioactive material 1802. For example, instead of having a separateradioactive sample inserted into the photon battery assembly (such as inFIG. 17), the radioactive material can be integrated in thephosphorescent material. By way of example, a phosphorescent materialcomprising strontium aluminate doped with europium can be manufacturedto have strontium-90 dispersed throughout the phosphorescent material.

The radioactive material 1802 can emit high energy particles from withinthe phosphorescent material 1801, such as products of radioactive decay.The high energy particles can travel through the phosphorescent materialupon emission from the radioactive material and excite thephosphorescent material (e.g., absorb the kinetic energy of the highenergy particles). The phosphorescent material can subsequently, after atime delay, emit optical energy. In some instances, the rate ofabsorption of kinetic energy by the phosphorescent material can befaster than the rate of emission of optical energy by the phosphorescentmaterial. As described elsewhere herein, the photovoltaic cell 1803 canabsorb such optical energy emitted by the phosphorescent material andgenerate electrical power. The electrical power generated by thephotovoltaic cell can be discharged to an electrical load 1806, such asthrough a port 1805 of the photovoltaic cell. In some instances, thephoton battery assembly 1800 can comprise an outer casing, shell orcompartment 1804 to house the phosphorescent material 1801 comprisingthe radioactive material 1802 and the photovoltaic cells 1803, such asto contain any radiation that can escape the energy storage systemduring normal use. The compartment 1804 can be configured to contain anyradiation emitted by the radioactive material 1802 from within thephosphorescent material 1801 from escaping the compartment 1804. Forexample, the port 1805 of the photovoltaic cell may be the onlyconnection from outside the compartment 1804 to inside the compartment1804.

In some instances, a photon battery assembly comprising radioactivematerial can provide higher energy storage capacity (e.g., energydensity, power density, etc.) than a photon battery comprising a lightsource after a single charge of the same volume. In some instances, theenergy storage capacity of a radioactive material comprising photonbattery assembly can depend on a half-life of a radioactive material inthe photon battery assembly. For example, a radioactive material canprovide continuous kinetic energy to the photon battery assembly as itundergoes radioactive transformation. In some instances, a photonbattery assembly comprising radioactive material can be disposed ofafter near full consumption of the radioactive material (e.g., emittingnegligent kinetic energy). In some instances, radioactive material canbe replaced after near full consumption. In some instances, thephosphorescent material and/or photovoltaic cells can be recycled (e.g.,in other photon battery assemblies) after near full consumption of theradioactive material. In some instances, a photon battery assembly cancomprise both radioactive material and a light source, and may berecharged via methods described elsewhere herein (e.g., providingelectric power to the light source). For example, even after near fullconsumption of the radioactive material, the photon battery assembly maybe used via recharging with electrical energy.

FIG. 10 illustrates a method of storing energy in a photon battery. Themethod can comprise, at a first operation 1001, emitting optical energyat a first wavelength (e.g., λ₁) from a light source. The optical energyat the first wavelength can be emitted from a light-emitting surface ofthe light source. The light source can be an artificial light source,such as a LED, laser, or lamp. The light source can be a natural lightsource. The light source can be powered by an electric power source,such as another energy storage device (e.g., battery, supercapacitors,capacitors, fuel cells, etc.) or another power supply (e.g., electricalgrid).

At a second operation 1002, a phosphorescent material that is adjacentto the light source can absorb the optical energy at the firstwavelength. The optical energy may be directed from the light source tothe phosphorescent material via a first waveguide. For example, thephosphorescent material can be adjacent to the light-emitting surface ofthe light source. In some instances, the first wavelength can be anultraviolet wavelength (e.g., 20-400 nm).

At a next operation 1003, after a time delay, the phosphorescentmaterial can emit optical energy at a second wavelength (e.g., λ₂). Insome instances, the first wavelength can be a visible wavelength (e.g.,400-700 nm). The second wavelength can be greater than the firstwavelength. That is, the optical energy at the first wavelength can beat a higher energy level than the optical energy at the secondwavelength. In some instances, the rate of absorption of the opticalenergy at the first wavelength by the phosphorescent material can befaster than the rate of emission of the optical energy at the secondwavelength by the phosphorescent material.

At a next operation 1004, a photovoltaic cell adjacent to thephosphorescent material can absorb the optical energy at the secondwavelength that is emitted by the phosphorescent material. The opticalenergy may be directed from the phosphorescent material to thephotovoltaic cell via a second waveguide. For example, a light-absorbingsurface of the photovoltaic cell can absorb the optical energy at thesecond wavelength. In some instances, the photovoltaic cell can betailored to absorb the wavelength or range of wavelengths that isemitted by the phosphorescent material. In some instances, thelight-absorbing surface of the photovoltaic cell can comprise one ormore depressions defined by corresponding protrusions to allow forincreased interfacial surface area between the phosphorescent materialand the photovoltaic cell.

At a next operation 1005, the photovoltaic cell can convert the absorbedoptical energy at the second wavelength and generate electrical power.In some instances, the electrical power generated by the photovoltaiccell can be used to power an electrical load that is electricallycoupled to the photovoltaic cell. The electrical load can be anelectronic device, such as a mobile phone, tablet, or computer. Theelectrical load can be a vehicle, such as a car, boat, airplane, ortrain. The electrical load can be a power grid. In some instances, atleast some of the electrical power generated by the photovoltaic cellcan be used to power the light source, such as when no electrical loadis connected to the photovoltaic cell. In some instances, at least someof the electrical power generated by the photovoltaic cell can be usedto charge a rechargeable battery (e.g., lithium ion battery), such aswhen no electrical load is connected to the photovoltaic cell. Therechargeable battery can in turn be used to power the light source.Beneficially, a photon battery assembly used in this method can be atleast in part self-sustaining and prevent loss of energy from the system(e.g., other than from inefficient conversion of energy).

FIG. 19 illustrates a method of storing energy in a photon battery. Themethod can comprise, at a first step 1901, emitting optical energy at afirst wavelength (e.g., λ₁) from a light source. The optical energy atthe first wavelength can be emitted from a light-emitting surface of thelight source. The light source can be an artificial light source, suchas a LED, laser, or lamp. The light source can be a natural lightsource. The light source can be powered by an electric power source,such as another energy storage device (e.g., battery, supercapacitors,capacitors, fuel cells, etc.) or another power supply (e.g., electricalgrid).

At a second step 1902, a phosphorescent material that is adjacent to thelight source can absorb the optical energy at the first wavelength. Forexample, the phosphorescent material can be adjacent to thelight-emitting surface of the light source. In some instances, the firstwavelength can be an ultraviolet wavelength (e.g., 20-400 nm).

At a next step 1903, after a time delay, the phosphorescent material canemit optical energy at a second wavelength (e.g., λ₂). In someinstances, the first wavelength can be a visible wavelength (e.g.,400-700 nm). The second wavelength can be greater than the firstwavelength. That is, the optical energy at the first wavelength can beat a higher energy level than the optical energy at the secondwavelength. In some instances, the rate of absorption of the opticalenergy at the first wavelength by the phosphorescent material can befaster than the rate of emission of the optical energy at the secondwavelength by the phosphorescent material.

At a next step 1904, a photovoltaic cell adjacent to the phosphorescentmaterial can absorb the optical energy at the second wavelength that isemitted by the phosphorescent material. For example, a light-absorbingsurface of the photovoltaic cell can absorb the optical energy at thesecond wavelength. In some instances, the photovoltaic cell can betailored to absorb the wavelength or range of wavelengths that isemitted by the phosphorescent material. In some instances, thelight-absorbing surface of the photovoltaic cell can comprise one ormore depressions defined by corresponding protrusions to allow forincreased interfacial surface area between the phosphorescent materialand the photovoltaic cell.

At a next step 1905, the photovoltaic cell can convert the absorbedoptical energy at the second wavelength and generate electrical power.In some instances, the electrical power generated by the photovoltaiccell can be used to power an electrical load that is electricallycoupled to the photovoltaic cell. The electrical load can be anelectronic device, such as a mobile phone, tablet, or computer. Theelectrical load can be a vehicle, such as a car, boat, airplane, ortrain. The electrical load can be a power grid. In some instances, atleast some of the electrical power generated by the photovoltaic cellcan be used to power the light source, such as when no electrical loadis connected to the photovoltaic cell. In some instances, at least someof the electrical power generated by the photovoltaic cell can be usedto charge a rechargeable battery (e.g., lithium ion battery), such aswhen no electrical load is connected to the photovoltaic cell. Therechargeable battery can in turn be used to power the light source.Beneficially, a photon battery assembly used in this method can be atleast in part self-sustaining and prevent loss of energy from the system(e.g., other than from inefficient conversion of energy).

FIG. 20 illustrates a method of storing energy in a photon battery usingradioactive material. The method can comprise, at a first step 2001,emitting high energy particles from a radioactive material. In someinstances, the radioactive material can be adjacent to a phosphorescentmaterial, in which case high energy particles are emitted into orreflected into the phosphorescent material. In some instances, thephosphorescent material can comprise the radioactive material, in whichcase high energy particles are emitted from within the phosphorescentmaterial. In some instances, the radioactive material can substitute tothe light source in some other embodiments discussed herein (e.g., suchas in the method of FIG. 19). In some instances, the radioactivematerial can be in addition to the light source. The radioactivematerial can emit high energy particles, such as products of radioactivedecay. The high energy particles can have high kinetic energy. The highenergy particles can travel through the phosphorescent material.

At a next step 2002, the phosphorescent material can absorb the kineticenergy from the high energy particles. For example, the phosphorescentmaterial can be excited by the high energy particles. At a next step2003, the phosphorescent material can, after a time delay, emit opticalenergy at a first wavelength (e.g., xi). In some instances, the firstwavelength can be a visible wavelength (e.g., 400-700 nm). In someinstances, the rate of absorption of the kinetic energy by thephosphorescent material can be faster than the rate of emission of theoptical energy by the phosphorescent material.

At a next step 2004, a photovoltaic cell adjacent to the phosphorescentmaterial can absorb the optical energy at the first wavelength that isemitted by the phosphorescent material. For example, a light-absorbingsurface of the photovoltaic cell can absorb the optical energy at thefirst wavelength. In some instances, the photovoltaic cell can betailored to absorb the wavelength or range of wavelengths that isemitted by the phosphorescent material. In some instances, thelight-absorbing surface of the photovoltaic cell can comprise one ormore depressions defined by corresponding protrusions to allow forincreased interfacial surface area between the phosphorescent materialand the photovoltaic cell.

At a next step 2005, the photovoltaic cell can convert the absorbedoptical energy at the first wavelength and generate electrical power. Insome instances, the electrical power generated by the photovoltaic cellcan be used to power an electrical load that is electrically coupled tothe photovoltaic cell. The electrical load can be an electronic device,such as a mobile phone, tablet, or computer. The electrical load can bea vehicle, such as a car, boat, airplane, or train. The electrical loadcan be a power grid. In some instances, at least some of the electricalpower generated by the photovoltaic cell can be used to charge arechargeable battery (e.g., lithium ion battery), such as when noelectrical load is connected to the photovoltaic cell. Beneficially, thephoton battery assembly used in this method can prevent loss of energyfrom the system (e.g., other than from inefficient conversion ofenergy).

FIG. 11 shows a computer control system. The present disclosure providescomputer control systems that are programmed to implement methods of thedisclosure. A computer system 1101 is programmed or otherwise configuredto regulate one or more circuitry in a photon battery assembly, inaccordance with some embodiments discussed herein. For example, thecomputer system 1101 can be a controller, a microcontroller, or amicroprocessor. In some cases, the computer system 1101 can be anelectronic device of a user or a computer system that is remotelylocated with respect to the electronic device. The electronic device canbe a mobile electronic device. The computer system 1101 can be capableof sensing the connection(s) of one or more electrical loads with aphoton battery assembly, the connection(s) of one or more rechargeablebatteries with a photon battery assembly, and/or the connection(s) of aphotovoltaic cell and a light source within a photon battery assembly.The computer system 1101 may be capable of managing the inflow and/oroutflow of power from each or a combination of photon battery assemblieselectrically connected in series or in parallel, and in some cases,individually or collectively electrically communicating with a powersource and/or an electrical load. The computer system 1101 may becapable of computing a rate of discharge of power from the photonbattery and/or a rate of consumption of power by an electrical load. Forexample, the computer system may be based on such computation, determinewhether and how to direct power discharged from a photovoltaic cell to alight source, an external battery (e.g., lithium ion battery), and/or anelectrical load. The computer system may be capable of adjusting orregulating a voltage or current of power input and/or power output ofthe photon battery. The computer system 1101 may be capable of adjustingand/or regulating different component settings. For example, thecomputer system may be capable of adjusting or regulating a brightness,intensity, color (e.g., wavelength, frequency, etc.), pulsation period,or other optical characteristics of a light emitted by a light source inthe photon battery assembly. For example, the computer system may beconfigured to adjust a light emission setting from a light sourcedepending on the type of phosphorescent material used in the photonbattery.

For example, the computer system 1101 can be capable of regulatingdifferent charging and/or discharging mechanisms of a photon batteryassembly. The computer system may turn on an electrical connectionbetween a light source and a power supply to start charging the photonbattery assembly. The computer system may turn off an electricalconnection between the light source and the power supply to stopcharging the photon battery assembly. The computer system may turn on oroff an electrical connection between a photovoltaic cell and anelectrical load. In some instances, the computer system may be capableof detecting a charge level (or percentage) of the photon batteryassembly. The computer system may be capable of determining when theassembly is completely charged (or nearly completely charged) ordischarged (or nearly completely discharged). In some instances, thecomputer system may be capable of maintaining a certain range of chargelevel (e.g., 5%˜95%, 10%˜90%, etc.) of the photon battery assembly, suchas to maintain and/or increase the life of the photon battery assembly,which complete charge or complete discharge can detrimentally shorten.

The computer system 1101 includes a central processing unit (CPU, also“processor” and “computer processor” herein) 1105, which can be a singlecore or multi core processor, or a plurality of processors for parallelprocessing. The computer system 1101 also includes memory or memorylocation 1110 (e.g., random-access memory, read-only memory, flashmemory), electronic storage unit 1115 (e.g., hard disk), communicationinterface 1120 (e.g., network adapter) for communicating with one ormore other systems, and peripheral devices 1125, such as cache, othermemory, data storage and/or electronic display adapters. The memory1110, storage unit 1115, interface 1120 and peripheral devices 1125 arein communication with the CPU 1105 through a communication bus (solidlines), such as a motherboard. The storage unit 1115 can be a datastorage unit (or data repository) for storing data. The computer system1101 can be operatively coupled to a computer network (“network”) 1130with the aid of the communication interface 1120. The network 1130 canbe the Internet, an internet and/or extranet, or an intranet and/orextranet that is in communication with the Internet. The network 1130 insome cases is a telecommunication and/or data network. The network 1130can include one or more computer servers, which can enable distributedcomputing, such as cloud computing. The network 1130, in some cases withthe aid of the computer system 1101, can implement a peer-to-peernetwork, which may enable devices coupled to the computer system 1101 tobehave as a client or a server.

The CPU 1105 can execute a sequence of machine-readable instructions,which can be embodied in a program or software. The instructions may bestored in a memory location, such as the memory 1110. The instructionscan be directed to the CPU 1105, which can subsequently program orotherwise configure the CPU 1105 to implement methods of the presentdisclosure. Examples of operations performed by the CPU 1105 can includefetch, decode, execute, and writeback.

The CPU 1105 can be part of a circuit, such as an integrated circuit.One or more other components of the system 1101 can be included in thecircuit. In some cases, the circuit is an application specificintegrated circuit (ASIC).

The storage unit 1115 can store files, such as drivers, libraries andsaved programs. The storage unit 1115 can store user data, e.g., userpreferences and user programs. The computer system 1101 in some casescan include one or more additional data storage units that are externalto the computer system 1101, such as located on a remote server that isin communication with the computer system 1101 through an intranet orthe Internet.

The computer system 1101 can communicate with one or more local and/orremote computer systems through the network 1130. For example, thecomputer system 1101 can communicate with all local energy storagesystems in the network 1130. In another example, the computer system1101 can communicate with all energy storage systems within a singleassembly, within a single housing, and/or within a single stack ofassemblies. In other examples, the computer system 1101 can communicatewith a remote computer system of a user. Examples of remote computersystems include personal computers (e.g., portable PC), slate or tabletPC's (e.g., Apple® iPad, Samsung® Galaxy Tab), telephones, Smart phones(e.g., Apple® iPhone, Android-enabled device, Blackberry®), or personaldigital assistants. The user can access the computer system 1101 via thenetwork 1130.

Methods as described herein can be implemented by way of machine (e.g.,computer processor) executable code stored on an electronic storagelocation of the computer system 1101, such as, for example, on thememory 1110 or electronic storage unit 1115. The machine executable ormachine readable code can be provided in the form of software. Duringuse, the code can be executed by the processor 1105. In some cases, thecode can be retrieved from the storage unit 1115 and stored on thememory 1110 for ready access by the processor 1105. In some situations,the electronic storage unit 1115 can be precluded, andmachine-executable instructions are stored on memory 1110.

The code can be pre-compiled and configured for use with a machinehaving a processor adapted to execute the code, or can be compiledduring runtime. The code can be supplied in a programming language thatcan be selected to enable the code to execute in a pre-compiled oras-compiled fashion.

Aspects of the systems and methods provided herein, such as the computersystem 1101, can be embodied in programming. Various aspects of thetechnology may be thought of as “products” or “articles of manufacture”typically in the form of machine (or processor) executable code and/orassociated data that is carried on or embodied in a type of machinereadable medium. Machine-executable code can be stored on an electronicstorage unit, such as memory (e.g., read-only memory, random-accessmemory, flash memory) or a hard disk. “Storage” type media can includeany or all of the tangible memory of the computers, processors or thelike, or associated modules thereof, such as various semiconductormemories, tape drives, disk drives and the like, which may providenon-transitory storage at any time for the software programming. All orportions of the software may at times be communicated through theInternet or various other telecommunication networks. Suchcommunications, for example, may enable loading of the software from onecomputer or processor into another, for example, from a managementserver or host computer into the computer platform of an applicationserver. Thus, another type of media that may bear the software elementsincludes optical, electrical and electromagnetic waves, such as usedacross physical interfaces between local devices, through wired andoptical landline networks and over various air-links. The physicalelements that carry such waves, such as wired or wireless links, opticallinks or the like, also may be considered as media bearing the software.As used herein, unless restricted to non-transitory, tangible “storage”media, terms such as computer or machine “readable medium” refer to anymedium that participates in providing instructions to a processor forexecution.

Hence, a machine readable medium, such as computer-executable code, maytake many forms, including but not limited to, a tangible storagemedium, a carrier wave medium or physical transmission medium.Non-volatile storage media include, for example, optical or magneticdisks, such as any of the storage devices in any computer(s) or thelike, such as may be used to implement the databases, etc. shown in thedrawings. Volatile storage media include dynamic memory, such as mainmemory of such a computer platform. Tangible transmission media includecoaxial cables; copper wire and fiber optics, including the wires thatcomprise a bus within a computer system. Carrier-wave transmission mediamay take the form of electric or electromagnetic signals, or acoustic orlight waves such as those generated during radio frequency (RF) andinfrared (IR) data communications. Common forms of computer-readablemedia therefore include for example: a floppy disk, a flexible disk,hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD orDVD-ROM, any other optical medium, punch cards paper tape, any otherphysical storage medium with patterns of holes, a RAM, a ROM, a PROM andEPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrier wavetransporting data or instructions, cables or links transporting such acarrier wave, or any other medium from which a computer may readprogramming code and/or data. Many of these forms of computer readablemedia may be involved in carrying one or more sequences of one or moreinstructions to a processor for execution.

The computer system 1101 can include or be in communication with anelectronic display 1135 that comprises a user interface (UI) 1140 forproviding, for example, user control options (e.g., start or terminatecharging, start or stop powering an electrical load, route power back toself-charging, etc.). Examples of UI's include, without limitation, agraphical user interface (GUI) and web-based user interface.

Methods and systems of the present disclosure can be implemented by wayof one or more algorithms. An algorithm can be implemented by way ofsoftware upon execution by the central processing unit 1105. Thealgorithm can, for example, change circuitry of a photon batteryassembly or a stack of photon battery assemblies based on, for example,sensing the connection(s) of one or more electrical loads with a photonbattery assembly, the connection(s) of one or more rechargeablebatteries with a photon battery assembly, and/or the connection(s) of aphotovoltaic cell and a light source within a photon battery assembly.The algorithm may be capable of managing the inflow and/or outflow ofpower from each or a combination of photon battery assemblieselectrically connected in series or in parallel, and in some cases,individually or collectively electrically communicating with a powersource and/or an electrical load.

While preferred embodiments of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. It is not intendedthat the invention be limited by the specific examples provided withinthe specification. While the invention has been described with referenceto the aforementioned specification, the descriptions and illustrationsof the embodiments herein are not meant to be construed in a limitingsense. Numerous variations, changes, and substitutions will now occur tothose skilled in the art without departing from the invention.Furthermore, it shall be understood that all aspects of the inventionare not limited to the specific depictions, configurations or relativeproportions set forth herein which depend upon a variety of conditionsand variables. It should be understood that various alternatives to theembodiments of the invention described herein may be employed inpracticing the invention. It is therefore contemplated that theinvention shall also cover any such alternatives, modifications,variations or equivalents. It is intended that the following claimsdefine the scope of the invention and that methods and structures withinthe scope of these claims and their equivalents be covered thereby.

What is claimed is:
 1. A system for storing energy, comprising: anassembly, comprising: a light source comprising an array oflight-emitting diodes configured to emit optical energy at a firstwavelength from a surface of the array of light-emitting diodes; aphosphorescent material configured to receive light from the array oflight-emitting diodes, wherein the phosphorescent material is configuredto (i) absorb the optical energy at the first wavelength, and (ii) at arate slower than a rate of absorption, emit optical energy at a secondwavelength, wherein the second wavelength is greater than the firstwavelength; and a photovoltaic cell adjacent to the phosphorescentmaterial, wherein the photovoltaic cell is configured to (i) absorboptical energy at the second wavelength through a surface of thephotovoltaic cell, and (ii) generate electrical power from opticalenergy; and a housing configured to contain the assembly while theassembly is in use.
 2. The system of claim 1, wherein the housingcontaining the assembly is portable.
 3. The system of claim 1, whereinthe housing is configured to contain the assembly having a maximumdimension of 1 meter.
 4. The system of claim 1, wherein the photovoltaiccell is electrically coupled to an electrical load and at least part ofthe electrical power generated by the photovoltaic cell powers theelectrical load.
 5. The system of claim 1, wherein a rechargeablebattery is electrically coupled to the light source and the photovoltaiccell, and wherein at least part of the electrical power generated by thephotovoltaic cell charges the rechargeable battery, and wherein at leastpart of electrical power discharged by the rechargeable battery powersthe light source, wherein the light source is further powered by a powersource other than the photovoltaic cell.
 6. The system of claim 1,wherein the phosphorescent material comprises strontium aluminate andeuropium.
 7. The system of claim 1, wherein the photovoltaic cellcomprises a plurality of depressions between protrusions and wherein thesurface of the photovoltaic cell is a surface of a protrusion defining adepression.
 8. The system of claim 1, wherein the surface of the arrayof light-emitting diodes is planar and flat.
 9. The system of claim 1,wherein the light source emits directional light that is directed towardthe phosphorescent material via a light guide.
 10. The system of claim9, wherein an air gap is provided between the light guide and thephosphorescent material.
 11. The system of claim 1, wherein thephosphorescent material is provided in a powder form.
 12. The system ofclaim 1, wherein the photovoltaic cell has a band gap tailored to thesecond wavelength emitted by the phosphorescent material.
 13. The systemof claim 1, wherein the assembly comprises a plurality of distinctvolumes of the phosphorescent material that receives light from thearray of light-emitting diodes, and wherein the photovoltaic cell isadjacent to a volume of the phosphorescent material.
 14. The system ofclaim 1, wherein the assembly is configured to power a plurality ofdifferent electrical loads as a battery.
 15. A method for storingenergy, comprising: (a) emitting optical energy at a first wavelengthfrom a surface of a light source; (b) absorbing, by a phosphorescentmaterial adjacent to and directly coupled to the surface of the lightsource, the optical energy at the first wavelength; (c) at a rate slowerthan a rate of absorption, emitting, by the phosphorescent material,optical energy at a second wavelength, wherein the second wavelength isgreater than the first wavelength; (d) absorbing the optical energy atthe second wavelength through a surface of a photovoltaic cell, whereinthe surface of the photovoltaic cell is adjacent to the phosphor; and(e) generating electrical power from the optical energy at the secondwavelength.
 16. The method of claim 15, wherein the light source is alight-emitting diode (LED).
 17. The method of claim 16, furthercomprising powering an electrical load electrically coupled to thephotovoltaic cell using the electrical power.
 18. The method of claim15, further comprising powering the light source using at least part ofthe electrical power, wherein the light source is electrically coupledto the photovoltaic cell.
 19. The method of claim 15, further comprising(i) charging a rechargeable battery using at least part of theelectrical power, wherein the rechargeable battery is electricallycoupled to the photovoltaic cell and (ii) powering the light sourceusing at least part of electrical power discharged by the rechargeablebattery, wherein the rechargeable battery is electrically coupled to thelight source.
 20. The method of claim 15, wherein the photovoltaic cellcomprises a plurality of depressions between protrusions and wherein thesurface of the photovoltaic cell is a surface of a protrusion defining adepression.